Rare and remarkable animals of Scotland, represented from living subjects: with practical observations on their nature

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RARE AND REMARKABLE ANIMALS

Of

SCOTLAND,

REPRESENTED FROM LIVING SUBJECTS

WITH

PRACTICAL OBSERYATIONS ON THEIR NATURE.

BY

SIR JOHN GRAHAM DALYELL,

BARONET.

VOLUME FIEST,

CONTAINING
FIFTY-THREE COLOURED PLAVES.

ROGicK coueaioM

LONDON:

JOHN VAN VOOEST, PATERNOSTER ROW.
MDCCCXLVII.

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,jvU.y ^"yj^

EIUNBURGH : PRINTED BV MACPHERSON .Si SVMK,

31 East Rose Lane.

CONTENTS

OF

VOLUME FIRST.

HYDRAOID ZOOPHYTES.

CHAPTER I. TnBULARIA INDIVISA, ..... I'ACIi 1

TUBULARIA LARYNX, . . . . . . 4il

CHAPTER II — TuBtiLARiA (Sertularia) RAMEA, ... 5(1

TuBULARiA (Sertularia) ramosa, . . . ()4

Medusa ocilia, ...... 6fi

CHAPTER III.— Hydra or Polypus, ..... 73

Hydra Tuba, Gelatinosa or Strobila, . • . 7G

Medusa, ....... 101

Medusa BIFIDA (minutissima), . . . 110

CHAPTER 17. — Sertularia — S. Polyzonias — Adieti.na— AniETixrLA — Ro-
sacea— PuMiLA — Halecina, . . 134-162
S. (Thoa) Beanii, . . . . . 163

Sertularia (Plumularia) falcata — Pinnata — Fascis, 176-18.5
S. Argentea, . . . . . .189

S. (Nemertesia) antennina — Ramosa, . . 198

CHAPTER V. — Campanularia — C. Dichotoma — Verticillata — Dumosa —

Syringa, ..... 211-223

S. Arcta, ...... 224

ASCIDIAN ZOOPHYTES.

Cellularia loriculata — Reptans — Fastigiata — Ciliata —

AvicuLARis, ..... 233-243

Aviculariuji, ..... 224

CLUSTER OR SOCIAL ZOOPHYTES.

Valkeria imbricata — CuscuTA — LeiNDIgera — Spinosa, . 24C

Index, ....... 257

ERRATUM.

Page 72, line 5, for duodeciliu read se.edecilia (ciUis sej:<lecein.).

PREFACE.

The substance of the following Treatise has been derived from a
series of observations, protracted during many years.

Its scope is limited, being restricted entirely to the natural produc-
tions of Scotland, which I feel desirous of rendering somewhat more fami-
liar to my countrymen, as those who must be the most interested in them.

The subjects introduced are comparatively few, from my entertaining
less solicitude for multiplying numbers, than for illustrating qualities.

We are prone, in general, to contemn the lower animated tribes, as
unworthy of notice and investigation.

But is it not arrogant to despise any portion of that stupendous
Creation, whereof we ourselves form only a single section ? Is it right,
that, dwelling amidst creatures occupying the same world, enjoying the
same Divine protection, alike provided with subsistence, and privileged to
prolong their race, we should remain in utter ignorance regarding them ?

The true philosopher beholds the hand of the Omnipotent imprinted
on every living being around him ; he finds nothing too humble whereon
to exercise those faculties benignantly bestowed on himself for enlarging
his mind by acquiring knowledge. Thence he will discover that to each
of the countless legions replenishing the world, along with his own exist-
ence, is appointed the fulfilment of a special part.

If the florist enjoys the bloom of those resplendent gems, which, void
of evident sensation and motion, yet stud the verdant fields, or decorate

b

vi PREFACE.

his gardens, and fill the air with fragrance, so much the higher should we
prize those living tenants of the deep, withdrawn to testify the action and
volition diffused throughout their beautiful and luxuriant flourish.

But this is only one of a thousand subjects adapted to invite our ad-
miration of the works of Providence.

Let us examine the marvellous structure of animated beings framed
for the maintenance of life ; the organs allotted for the prehension, the
reception, the internal preparation and distribution of the food for nutri-
ment, and the benefit which it imparts. Let us contemplate the other
animal functions, all relative, co-operative, and effective towards producing
a common end, we are astounded alike at the contrivance and the execu-
tion. " How could this originate !" we exclaim. " How could such an
edifice be reared, but by some Supreme Architect .'"

Still, is this glorious edifice doomed to perish ? Every year, every
hour, nay, each moment, is advancing it to decay. AVhy should it be so ?
Death is the necessary consequence of life. Were not multiplication
balanced by destruction, the earth would be soon overrun — incapable of
sustaining its tenants : Nor can the human imagination figure that space
sufficient to receive them to eternity. But while the lesser structure
perishes, the foundation remains. To living nature is committed the means
of replenishing the waste.

In endeavouring to ascertain the history of the animated tribes, it
must be prosecuted from their origin to the close. We should behold
them under the nearest possible circumstances to their mode of life in
their natural abode. This, indeed, may be difficult But spite of that
tenuity of many humbler beings which almost eludes the observer's gaze,
of that delicacy and fragility almost precluding his touch, their retreat
from the light of day, and feeling the gentlest treatment too rude, patience
and perseverance will infallibly reward his diligence.

The more important features to be considered, are form, feeding,
breeding, and the habits of animals. The form cannot be otherwise de-
monstrated than by the living subject. The food being seldom present
with the creature, is often to be found only by accident ; the breeding may
be seen from opportunity, though long sought in vain ; and the exhibition

PREFACE. vii

of habits is dependent on so many contingencies, as to require the careful
preservation of life under the best conditions.

From such indispensable requisites for a Treatise on Natural History,
it is obvious that the taste and qualifications of the historians of each must
be diversified in their respective departments, that their opportunities
shall be favourable, and their labours protracted.

The operations of Nature undisturbed, are those which demand our
confidence. The real organization and habits of the inferior tribes are
never displayed unless in a tranquil, vigorous, and healthy state. When
under constraint, placed in an unsuitable medium, or enfeebled by disease,
the finest specimens languish : they alter and contract, the relative position
of their parts is disturbed, their functions are impaired : the organs most
conspicuous or most important during life, often disappear entirely, or they
are changed by death, beyond the hope of recognition. Thence can we
do otherwise than reprehend and distrust the cruel operations and assumed
results whereon too many modern anatomists have founded theories, from
living animals — rather from animals in the agonies of death !

It is vain for one individual to claim the concentration of so many
qualities as are necessary for the illustration of the natural history of even
a single subject of the animal world ; whence, conscious of the superiority
of my more distinguished fellows in the science, I confine myself to a
narrow sphere.

My principal aim has been to render the external aspect and the
habits of certain species of the lower orders more familiar to others, and
especially to those who may not have had equal opportunities of personal
observation.

In doing so, I have endeavoured to select the most vigorous living
specimens of their kind ; and along with a general description, to present
their resemblance from delineations by the most skilful artists. Nothing
is described, nor scarcely alluded to, unless represented ; for it is irksome
to read of what cannot be otherwise understood.

By suitable precautions, I have been enabled to preserve individual
subjects, one, two, nay, even ten or twenty years, and, by this long ac-
quaintance, to gain some information of their character.

viii PREFACE.

The suitable mode of preservation depends on the nature of the race.
But, after supplying their native element, first, the observer must guard
against those destructive propensities of many of the lower animals,
prompting them to wage war on each other. The Cnistncea and the
Actinia are fell devourers of whatever they can overpower. The Asterias,
and the Echinus, and some of the leeches, are ravenous of prey. But the
Holotliuria, the Amphitrite, TerebeUa, and the whole ascidian tribes, seem
perfectly harmless.

The element wherein the captives are kept should be always recent,
generally pure, the vessels clean, and free of tainted matter. Some fall
immediate victims to putrescence ; others can resist it wonderfully, either
endeavouring to escape by ascent, or by descent, according to their pe-
culiar nature, or closing themselves up as if to avoid its deadly influence.
The water for most of the Crustacea should be free of mud, and contain
eminences whereon they may rest at will, above the surface. But muddy
solutions are essential to most of the bivalve Testacea, and to all the as-
cidian tribes, unless belonging to some of the foliaceous or other zoophytes.
Such solutions are grateful to certain Amphitrite, to many Vermes, as
sand is to various species of the Nereis. Capacious vessels are commonly
beneficial, and within them should be shells or stones for retreat and shel-
ter. The presence of the common Lepas of the shore, is useful as an in-
fallible guide, by its display, to the purity of the water.

The naturalist's earliest care ought to be obtaining an accurate de-
lineation of his subject — always selecting the finest specimen — and taking
it in motion, or when the parts are best unfolded. Herein it is prefer-
able to employ another's talent than the naturalist himself, though a skil-
ful artist. Many delusions are ever ready to mislead, but of two observers,
each may correct the other. After delineation, the subject can be stu-
died at leisure.

Respecting the representation itself, where indispensable to havefigures
larger than life, that is, as shewn by lenses and microscopes, nothing more
is requisite than what will favour distinct inspection. There, the author
and the artist should stop. We are now less removed from the reality.
Preservino- distinct vision, perhaps diminution will be preferable to

PREFACE. ix

enlargement, just as a miniature of the human visage is more agreeable
than one of colossal size. Besides, certain subjects become indefinite in
proportion to the magnifying powers ; where these are very high, unequal
surfaces cannot be brought within a common focus. In general, the lower
the power the better.

All specimens ought to be healthy, vigorous, and entire. A portion
is seldom a satisfactory type for the whole. As the truth and accuracy of
observation depend greatly on the number and quality of specimens, one
only should not content the naturalist, nor should he dispense with many.
Delineation ought to be the inseparable companion of description.

I have endeavoured to practice this rule throughout, from conviction
of its utility.

Among many accomplished artists to whom this work is indebted, I
cannot omit the late Mr Peter Syme, an eminent flower painter, who last
superintended the academical department of his particular pursuits at
Dollar, — also the late Mr Alexander JMacaulay, an amateur who devoted
much of his time to similar studies, — Mr John Welch, an excellent minia-
ture painter, whose exquisite productions from the microscope are entitled
to the highest admiration, — likewise Mr Andrew Thom, presently occu-
pied in paintings for the Stained Glass Windows of the House of Lords,
whose accuracy and patient diligence exceed all commendation.

It is not without diffidence that I venture to offer the following frag-
ments to the public, seeing that there are numbers of the scientific world
so much better qualified for the task My purpose is repeatedly explained,
as designing them to be viewed only as some detached Memoirs, com-
posed from an accumulation of facts.

I profess no more than to speak of the living subjects I myself have
beheld, and such as belong to Scotland. I disclaim all pretensions to dis-
covery. I think, indeed, it would be difficult to name the first observer
of Nature's offspring, whose race has existed since the beginning of time.
If speaking personally of subjects occurring to me, it is by no means to
disparage other naturalists, to whom I shall always render the homage
due : if omitting quotation of the works of celebrity, it is from my inabi-

X PEEFACE.

lity to procure them, nor will their candid authors impute it to disrespect.
Men gain nothing by depreciating their fellows.

A treatise such as the present must be necessarily impaired by many
inequalities. Lists of synonyms, so copiously introduced in the valuable
writings of Lamarck and Dr George Johnston, become less important here,
where every subject described is represented. Likewise, as the structure
of the skeleton of zoophytes is very obscure during life, little is said of it,
from being so copiously illustrated by this last named author, by M. de
Blainville, an eminent French naturalist ; and nearly a century ago by
Ellis.

There may be numerous deficiencies in nomenclature : Nor do I
entertain so great a reverence for new names, as immediately to abandon
the old. Most of the arts and sciences, it is true, have a jargon peculiar
to themselves, tending too much to obstruct the facility of their acquisi-
tion, though useful when conquered. But nothing can be more appalling
to the eager student, in quest of knowledge, than a repulsive array of un-
intelligible phrases, intercepting the objects of curiosity from his under-
standing. Those familiar with names never think of enquiring after roots,
nor would the greater part be easily comprehended if found. The lan-
guage of social intercourse remaining unchanged, proves it sufficiently ex-
plicit without recurrence to roots for its derivation.

Neither have I hurried after the multiplication of genera, which now
so freely adopted, will probably lead to such embarrassment, that an epoch
may not be distant, when the more enlarged views of succeeding natura-
lists shall concentrate their number, by restoring the disjointed members
to their previous position.

The sciences benefit little from the mere enumeration of a multitude
of species by name, which must be held as a meagre substitute for the
shortest commentary on their nature : Neither can the most copious de-
scription of living creatures convey an adequate knowledge of their form
without repi-esentation.

The progress of science is very slow. New observations are seldom
diffused in less than seven or ten years, unless those hasty and sometimes

PREFACE. XI

inaccurate contributions to periodical publications. Dr Samuel Johnson,
the lexicographer, remarks of the singularities of a cavern in the Hebri-
des, that he there saw what he had never seen before, " limpets and mus-
sels in their natural state,"^an example of how little the most familiar
objects are known !

If the naturalist expects ready confirmation of his discoveries or ob-
servations, he must occupy himself with subjects of easy acquisition, — with
those which are not rarities. The common store of knowledge might be
also enlarged by bestowing more attention on the productions of our own
immediate districts, instead of seeking after those at a distance. Things
common to us, may be to others very rare.

Some of the most desirable animals are frequently of the most diffi-
cult attainment. But the majority of living creatures are local : Food,
soil, and climate, have spread them over the earth, and lodged them amidst
the waters. A modern French author expresses his surprise, that the
scarcity of a certain zoophyte, plentiful in his own country, should have
embarrassed an English naturalist. If I mistake not. Professor Delle
Chiaie, a learned Italian, affirms, that, from the Bay of Naples, he had ob-
tained 2000 Holothuriae, — an animal so rare in most of the British seas,
that very few of our naturalists can say they have ever seen it alive. Though
having myself been more fortunate, for at least 150 of different species
have fallen into my possession, some of them surviving for years, it will be
seen in the course of these Memoirs, how little information I can offer on
the subject beyond those faithful representations after Nature, which I can
find nowhere else : — Or how meagre my narratives of the Lohularia,
Terebella, Amphiirite, and many others, tliough year after year was
anxiously devoted to enquiries regarding them.

Of various other animals, I can do scarcely more, if so much, as
skilful authors have left nothing important, besides, to illustrate their his-
tory. It is by uniting fragments that regular narratives are completed.

The sedulous naturalist must advance with a steady pace ; he is not
to be deterred from description, because unable to compose a dissertation :
nor abandon his dissertation, from wanting illustrative views at the mo-
ment to confirm it. He must often renew his task, though often inter-

xii PREFACE.

rupted : Nor easily discouraged, ought he ever to forsake his pursuit as
hopeless. If it be difficult to determine truth, from the time and trouble
of ages, how should we be guarded from error by negligence and preci-
pitation ?

Those who are animated by the love of science, who are endowed
with liberality and learning — and, above all, the pious, who bow in venera-
tion of the mighty Power of the Creator, will justly appreciate the true
import of this Treatise, though impaired by the numerous defects insepa-
rable from the works of mankind.

RARE AND REMARKABLE ANIMALS.

ZOOPHYTES, OR ANIMALS RESEMBLING PLANTS.

CHAPTER I.

The waters of the world teem with organic life : the depths of the
ocean harbour the most beautiful, rare, and remarkable productions ;
marshes, rivers, lakes, and fountains swarm with an host of animated
beings, whose varied forms and isolated habits unfold another universe,
pregnant with inexhaustible sources of enjoyment to the contemplative
mind.

On surveying the legions thus dispersed, we are absorbed in admira-
tion of the profound, the grand and uniform design which obviously
regulates their existence. Each has its appointed time and place. No
deficiencies restrain the action of those, but so many simple atoms to
our imperfect senses, void of external or subordinate parts. No embar-
rassments confuse the exercise of what to us seem useless, unmanageable,
or redundant organs : nothing precludes the operation of such functions
as are essential for self-preservation, and the continuance of their race.
Each has that perfection which is necessary for it individually, while

VOL. I. A

2 ZOOPHYTES.

forming a portion of that harmonious whole wherein all are compre-
hended.

Entire tribes, as yet unnamed, — and many yet unseen, — incessantly
originate, and flourish, and decay, where most remote from notice, or
most inaccessible to mankind. When casually withdrawn from their
recesses, it is as if in derision of our vaunted knowledge, and to prove
our ignorance of the wonderful works of creation. Now the entire aspect
of animated nature changes before us.

1. TuBULARiA Indivisa. — The Simple Tuhularia, or Oaten Pipe Co-
ralline.*— Plates I., II., III., IV. — An animal product, which the super-
ficial observer might conclude a flourishing vegetable, dwells at the depth
of thirty or forty feet from the surface of the sea. This, a yellow fistulous
stem, full of mucilaginous pith, is rooted on a solid substance below, and
crowned by a living head, resembling a fine scarlet blossom, with a double
row of tentacula, and often with pendent clusters like grapes, embel-
lished by various hues, wherein red and yellow predominate.

Though perfect as a single stem, this production seldom appears in
a solitary state, — two, three, fifty, or even an hundred and fifty stalks
crowded together, — their heads of diverse figures, shades and dimensions,
constitute a brilliant animated group, too rich in nature to be effectively
pourtrayed by art. Plate I.f

The stalks of a numerous colony are frequently intertwined towards
the root, which runs as a mere prolongation of the stem, on the subjacent
substance, or descends over its side, in a tortuous form, in strong adhe-
sion ; but always destitute of radicles like those rivetting vegetable pro-
ducts to the earth. Many of the stalks deviate from perpendicularity by

* This may be defined, " Hydra sustained on a fistulous stem, wherein it is not re-
tractile. Tentacula in two rows : ovarium interposed between them."

t All the subjects described here, being represented from living specimens, renders
a list of synonyms superfluous. The reader will find great assistance from the works of
Ellis, the Rev. Professor Dr John Fleming, Dr George Johnston, Lamoroux, La-
marck, and other learned authors.

pr..jrii. I.

C. >yy/f//,y W O "n//i''i/t^a. .

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TUBULARIA. 3

great incurvatures as they rise, bending at right angles, waving in serpen-
tine forms, or quitting and resuming their original direction. All enlarge
slightly upwards.

The head is a hydra or polypus, the general nature of which extra-
ordinary race shall be afterwards illustrated. It consists of a central
pouch or stomach, amidst a row of tentacular organs, which may be con-
veniently denominated palpi, nearly as numerous as another external mar-
ginal circle of from 1 5 to 35 larger tentacula or feelers, the number vary-
ing according to the specimen. — Plate III. fig. 1, a, b. The orifice of the
stomach, rarely shown, when dilated exposes an internal dark red ring.
Interposed between these two rows of larger and lesser feelers, and ap-
parently originating from the external lower part of the stomach, are seen
the ovaria, resembling minute protuberances in the beginning, and pen-
dent clusters on reaching maturity. Their peculiar position in the vici-
nity of the stomach is a fact of much interest, when the analogies con-
necting the different species of hydra are investigated.

But, notwithstanding the ornamental aspect of the product, and the
strict resemblance of the whole to a bouquet of vivid flowers from the
hand of nature, there is no uniformity in the quality or proportion of its
various parts ; nor are any definite principles affecting either its luxu-
riance or its meagreness sufficiently understood. — Plate II. figs. 1,2, 3, 4 ;
Plate III. fig. 1.

The tallest specimens rise thirteen inches high, by about a line where
thickest, — the height of the stalk being thus equal to 156 times its
diameter; and the head expands 14 or 15 lines between the opposite
tips of the tentacula.* But the height and diameter, the general luxu-
riance and the fertility of the product, have no reciprocal dependence on
each other. The largest head is commonly borne by the largest stalk.
Some of the finest appear, nevertheless, on stems only two or three inches
high, very slender, and with scanty pith, the abundance of which substance
is for the most part essential to vigour. Recurvature of the tentacula

* The finest specimens are always to be understood, when describing the dimensions
of animals. I speak only of tliose occurring to myself.

4 ZOOPHYTES.

denotes salubrity : their ruddy hue then descends a portion of the stalk,
which is often longitudinally striated above, and of a rich orpiment colour,
fading downwards.

The organs of prehension, nutrition, and propagation belong to the
hydra, or head of the Tubularia. Here also is vitality demonstrated, by
its turning from side to side, by the various tentacular motions, the action
of the oral palpi, distension of the stomach, and discharges of half-
digested food from its orifice, which may be held as the animal's mouth, —
an incident seldom witnessed. But, excepting in its own immediate vici-
nity, the head exercises no sensible influence over the stalk ; neither has
the latter any vacant cavity for its reception, as some have been led to
believe, from inaccurate description of the parts, nor can it be retracted.

This Tubularia commonly occurs in society, resulting perhaps from
its mode of propagation, where the oldest and the youngest are approxi-
mated in the same group. As every separate stem enlarges insensibly
upwards, the intertwining roots are concentrated within a limited spot
below. A colony composed of 55 stalks, diverging five inches above, was
rooted within the diameter of an inch. None rose above six inches ;
32 were fine flourishing heads ; 23 stalks were vacant. Another colony,
occurring in 1843, consisting of 140 stalks, might have been received in
a vessel seven inches high, of a quadrangular form, four inches wide, and
under two across. The concentrated roots were limited to an area of an
inch and a half by an inch. Great inequality prevailed among these spe-
cimens, nor were any luxuriant.

Specimens are generally founded on shells, entire or decayed, empty
or tenanted. The latter seldom appear. A brilliant group once occurred
on a shell which was carried along in its course by the crawling inhabi-
tant. As few vegetate on stones, the calcareous matter of shells may
be more favourable to evolution.

Reproduction of the head. — Though some later naturalists object to
the application of the name of this portion of the animal frame, in de-
scribing the lower orders, it is a distinction too convenient, brief, and ex-
plicit, to be precipitately abandoned.

When the head of the Tubularia has attained complete maturity from

TUBULARIA. o

age, or increment, the tentacula become much recurved, their wonted re-
gularity is impaired, and their extremities exhibit approaching decay.
The pendent ovarian clusters spread luxuriantly over them ; the central
pouch, as if its faculties were exhausted, is empty and contracted, the
whole betrays a languishing, sickly aspect. Next, a point of intersection
may be discovered amidst the ruddy pith near the summit of the stalk ;
and the head soon separating there, falls amidst the surrounding element,
but not to perish immediately : demonstrations of life continue during
many hours ; nay, they are protracted for eight days or longer in vigorous
specimens.

Some analogy with the form of the simple hydra may be now recog-
nised in this separated portion ; and we shall afterwards find a correspon-
dence between its condition and that of the nascent product in its earlier
stages. But neither has the short stump, under the head, which is drawn
from the stalk by separation any adhesive faculty ; nor are the feelers of
that extensile nature or prehensile power belonging to those of the hydra
proper. Indeed, in their best and most vigorous state, their property is
rather adhesive than prehensile, in regard to other objects.

Meantime, the florid summit of the vacant stalk is fading ; a kind of
cicatrix closes the wound. But on the lapse of a certain interval, it
darkens again ; an internal bud is advancing, which speedily ascending,
bursts a transparent involucrum, and flourishes as a new head, precisely
from the same point whence its precursor had fallen, and of equally vivid
hue.

Singular, to be told, the regenerative faculty is not exhausted here ;
for, after subsisting an indefinite time, this second head droops and dies,
and is dissolved on its fall. Then it is replaced by a third, and the third
by a successor. How often the like may be repeated — how many succes-
sive heads may be generated anew, throughout the whole life of the zoo-
phyte, cannot be readily ascertained, and that for various reasons.

All marine productions dislodged from considerable depths are liable
to the greatest injury. Though casually obtained clean and entire, most
of them are profusely invested by parasites, which, fatally and invisibly
wounded, speedily corrupt the circumambient fluid in their decay. Even

6 ZOOPHYTES.

under the best conditions, no trivial embarrassments impede the artificial
conservation of delicate creatures abounding in the sea. The water,
also, sometimes contracts a noxious principle, from causes eluding conjec-
ture and observation. But it may be fit to warn the naturalist against
employing tall vessels, with copious vacuities above the water, on all occa-
sions ; for, if the air, vitiated by respiration, escaping from the surface, be
re-absorbed, it cannot be otherwise than deleterious. This is well illus-
trated by attempting to keep fishes in deep vessels, with a scanty propor-
tion of water, to prevent their leaping over the side. They generally
perish in a short time ; and hence shallower vessels nearly full are prefer-
able.

Five successive heads have vegetated from the same stem of a speci-
men of this Tubularia in captivity, without computing those necessarily
borne, as the medium of its previous prolongation. But it is not to be
inferred that the reproductive power was then exhausted, for one so pro-
lific, in the brief period devoted to observation, may regenerate ten or
twelve times during the course of its existence.

Some remarkable facts attend renewal of the head ; and first, the
prolongation of the stem seems absolutely dependent upon it. Having lost
its head, the stem to all appearance remains stationary, unless in the wound
closing ; but from the moment that the rising internal bud reaches the
vacant extremity, in its integument, the neck, or that portion sustaining
this young hydra, visibly lengthens, and so continues, until further pro-
longation is arrested, by the separation and fall of the regenerated parts.
The wound cicatrizes again. If reproduction follow, by another embryo
rising within to issue from the summit, a new prolongation ensues also ;
and so on with a third, a fourth, or more. Thus are formed as many nodes
or articulations of the stem.

Prolongation of the stalk seems combined with the evolution of the
hydra by one of the few invariable laws ascertained. But the irregular
duration of the successive hydrse or heads, produces an irregularity in the
accessions to the length of the stalk. One shoot extending six or eight
lines may be followed by another of only two or three ; and the prolonga-
tion seems scarcely sensible where the head flourishes merely to decay.

TUBULARIA. 7

The Utmost dimensions of this product are therefore as uncertain as the
number of regenerated hydrse whereby they are attained. Let it be al-
ways remembered, that the prolongation of the hydra's neck is the sole
medium of extension of the stem.

The tallest of a group in confinement had reached five inches in five
months, after regenerating five heads ; whence it must have borne at least
six, including the first or original head. Instead of one, however, there
might have been more. With greater care, this specimen might have
proved more prolific. Others of the same group continued flourishing
during a whole year by hydrse regenerating.

Where no articulation or node indicates the origin of a shoot through-
out two or three inches, either the head has never fallen, or, on reproduc-
tion, the neck has been incorporated so intimately with the stalk, as to
render the place from whence it issues imperceptible. The head has
never been so permanent in confinement as to show that such remarkable
elongation can result from the existence of a single regeneration.

The renovated shoot is flexible, especially towards the head. Greater
rigidity ensues, as also of the lower portion of it, and the colour fades
with time.

The reproduced hydra certainly originates below, as shall be after-
wards illustrated ; and sometimes the transparency of the stem exposes
the ascending embryo while yet at a distance from the summit. Defec-
tive vigour may render its ultimate evolution abortive.

Regeneration of the head is an important process in the arrangements
of nature, from its being the site of not only the organs essential for nu-
trition of the individual, but of those instrumental in the conservation of
the race.

Propagation. — Several florid clusters, resembling minute bunches of
grapes, with three, seven, twelve, or more berries in each, weigh down the
most luxuriant heads. These constitute the ovarium, composed of so
many capsules or cysts, each in an advanced stage, containing a single
embryo or foetus. The greatest disparity of size and number prevails
among the cysts and the clusters, nor are they of uniform figure. Cysts,
as mere protuberances, are associated in some bunches with those whose

8 ZOOPHYTES.

contents approach maturity. Generally, they are somewhat lanceolate, or
resembling an inverted pear. Each cluster is suspended by a hollow stalk
from the lower part of the stomach in its vicinity ; and each cyst hangs
by a pedicle from this stalk.— Plate II. figs. 2, 3, 4, 5; Plate III. fig. 1.
Clusters 2-4, 6-8, natural size : Magnified, 3, 5, 7, 9; also fig, 16.

The internal ovum seems connected with the stalk suspending the
bunch through the medium of its pedicle, which penetrates the cyst.
Perhaps this connection may be such as of the embryo in the vesicles of
the Sertularia, with what later naturalists denominate the placental co-
lumn.

The integument of the cyst is rather of a fleshy consistence, either
opaque, or so thin and semi-transparent as to expose its contents. — PI. III.

fig. 9.*

Each contains a single embryo or foetus, which on maturity is expelled
slowly and gradually, as a minute, white, solid substance, from a dilateable
orifice at the extremity.— PI. III. figs. 10, 11, 12, 13.

I was long doubtful whether two were not included in a single cyst,
especially as a dark septum seems to divide it. But one only in a spheri-
cal or ellipsoidal form belongs to each. Some are not half as large as
others.— PI. III. figs. 14, 15.

Soon after expulsion an irregular zone or waving line may be recog-
nized on the circumference of the embryo, which, within a day, denotes
orioinating tentacula. In earlier stages the animal resembles a star with
obtuse rays, or the spokes of a wheel ; figs. 20, 23. The centre is next
prolonged in opposite directions : on the one side as extending oral palpi,
on the other as the neck or stalk of the hydra.

But these are of slower progress ; and meanwhile the discoidal or
circumferential tentacula exhibit enlarged extremities in their elongation,
whereon the nascent animal sustaining itself, reversed from the ultimate
natural position, can voluntarily change its place. Now, the central por-
tion forming the stomach augments in length, and decreases in thickness ;

* Considerable latitude must be allowed to tlie signification of fleshy, mebranaceous,
gelatinous, and the like.

TUBULARIA. 9

as prominences indicate originating palpi, the swelling extremities of the
tentacula refine into points : the animal, still a simple hydra, endowed
with locomotive faculties, reverses its position, and becomes permanently
rooted on the plane supporting it.

Such is the issue of the process generally followed by Nature, and
that sometimes within twenty-four hours of expulsion of the embryo from
the ovarian cyst. — PI. III. figs. 20-26.

But sometimes, also, the embryo is retained in the cyst until de-
velopement is discovered by partial protrusion of the tentacula from its
orifice.— Figs. 16, 17, 18. a.

As most naturalists deny that the inferior animals are truly vivi-
parous, they may ask. Whether an ovum, an embryo, or a foetus, has been
thu* expelled, particularly as the use of these characters is often too indis-
criminate. By an ovum may be understood a certain organic formation,
derived from the parent, involving the elements of a germ susceptible of
the institution of life : — by an embryo, that evolution of the germ into
such definite form as may be recognised by the beholder ; — and by 2, foetus
that approach to maturity by the development of those essential organs
which shall admit protracted existence, and the means of maintaining it
after separation from the parent.

But nothing can be more obscure than the precise nature of what we
denominate the germ : whether it be a recent organic atom, derived im-
mediately from the parent, by some secretory process, and lodged in an
invisible cyst or cell ; whether of primordial origin it has subsisted as an
atom, until the successive maturity or decay of preceding atoms wherein it
was involved has set it free, that now, from concurring circumstances and
conditions- its own evolution may ensue. Neither is the commencement
of the embyronic state to be sufHcieutly defined, farther than signifying
the sensible formation of parts to be modelled for their respective functions
in final perfection.

Nevertheless, we may conjecture that the germ is a vascular speck,
originally eluding the observer's view, which becomes susceptible of the
institution of life on attaining some certain stage or condition of its ex-
istence ; that the presence of life admits the evolution of the various

VOL. I. B

10 ZOOPHYTES.

parts, by the incorporation of matter derived from the parent, and that
through the medium of what constitutes the other substance of the ovum.
But how the spark is kindled, and especially how life is instituted in what
is derived from androgynous beings, — as well as where Nature has deter-
mined different sexes, is wrapped in impenetrable mystery.*

The transparence incident to originating beings, denoting extreme
tenuity, gradually diminishes as their rudimentary organization expands
and consolidates. Whence, an embryo next recognised in advance to a
foetus is seen under definite form, and the foetus is at length ushered into
independent life.

But were it not for other conditions, apparently more depending on
chance than arrangement, life shall never glow, nor can maturity follow ;
and these affect the largest, the most valuable, and most important pro-
ducts of Nature equally with those deemed utterly insignificant by the
mass of mankind.

Though the elementary germ be susceptible of impregnation, or al-
though by germination it may unfold as a bud bursting from the parent,
unless for a certain degree of temperature evolution cannot ensue. Heat
is a positive condition : it is indispensable for its organization acquiring
sufficient capacity for nutrition, and the consequent benefit.

Should the progeny be considered an ovum on expulsion, instead of an
embryo or foetus, that state is very transient, for it resolves almost imme-
diately into another form by the evolution of other parts. If casually re-
tained in the cyst, its expulsion as a foetus quickly follows.

All regenerated portions of the adult are at first invested by a trans-
parent spath ; nor is it improbable that some delicate amnios surrounds the
organic substance expelled from the cyst, whose presence is disguised by
excessive tenuity.

Nothino- can be more remarkable to the spectator than finding the
progeny free, while the parent is immoveably rooted — sufficient evidence
that thereis nothing of vegetable nature in such zoophytes. It is as strictly

* I am not ignorant of what is a modified theory of older date, much insisted in of

late, that a minute creature, whose parts elude human observation, finds a nidus in the

ovum, and thence becomes the real source of future increment and organic vitality, — also
that a being reputed androgynous may fructify itself.

TUBULAEIA. 11

an animal product as an alcyoniiim or an ascidia, whose original corpusadum,
planula, spinida, larva, or by whatever name may be given, which by nature
becomes rivetted to some solid sustaining foundation.

The nascent tubularia thus free, and capable of selecting its position,
loses that faculty never to be regained and is rooted at an indefinite period
— sometimes in the course of one day, sometimes on the lapse of two. But
quiescence is essential here. Should frequent disturbance alter its place,
the adhesive power seems to be impaired, or the creature rendered inca-
pable of its exercise. The increment of those which are rooted in early age is
commonly much more rapid than that of others. Specimens discharged
from the cyst on the 1st of January, and affixing speedily, were about four
lines high in seven days. Those whose adhesion had not ensued were in-
finitely smaller. With the latter, it is not improbable that, instead of the
softer extremity vegetating downwards and remaining susceptible of adhe-
sion, it becomes invested on exposure by an intercepting epidermis.

At the stage of early adhesion, the tentacula, which are 14 or 16 in
number, appear alternately set as in a higher and a lower circle ; and the
stem is somewhat of variable figure — both probably indicating the softness
of the parts or the result of it.

All nascent Tubulariae are of the palest grey ; and for the first fort-
night, the length of the tentacula and general dimensions of the hydra are
proportionally greater than in adults. But the stem is seldom straight ;
sometimes also, irregularities are seen near the root, which, as already re-
marked, has no radicles. — Plate III. fig. 28 : The same enlarged, fig. 35.

The head of the nascent tubularia falls after an indefinite period, just
as with the adult. But life is so feeble here, that the first is rarely re-
placed by a successor. That of a specimen bred from the ovum in April
1825, fell eleven days from its evolution ; but one bred in January 1841,
subsisted thirty-seven days, being longer than any other.

A nascent tubularia, with a flourishing head of fourteen or fifteen ten-
tacula, regenerated one with only seven, which fell on the third day, and
was not replaced. — Plate III. fig. 39. Another, bred from an ample ova-
rium, was so firmly rooted in two days that its vessel might be safely
emptied. It had fifteen tentacula, which extended a line a week later ;

12 ZOOPHYTES.

the whole product being white and very vigorous : the head fell in twenty-
one days from the first, leaving the stalk nearly four lines high. In seven
days it was suceeeded by a second, also pure white, but with only eight
tentacula. This subsisted eleven days, without acquiring the vigour of its
precursor :-^Plate III. fig. 40 ; enlarged, fig. 41, distinctly shewing the
ascent of the neck from within. In a recent instance the second head of
a nascent specimen was developed with six tentacula.

Considerable difference is presented by the aspect of different nascent
animals from the cyst, and especially in the curvature of the stem, so sel-
dom straight, which may be influenced by the hardness and smoothness of
the glass, whereon in this artificial state it was founded throughout the
course of my observations. — Figs. 20-41.

There are also considei'able disparities in the comparative dimensions
of the head with the rest of the product ; — as well as in the comparative
rates of increment of those which are fixed or free, — all resulting, per-
haps, from the pabulum afforded by their respective site. Of four nascent
tubularise, produced in April, two had seventeen tentacula, one fifteen, and
the other fourteen. The last never adhered, but it grew more rapidly, and
on losing its head, had extended half an inch, — exceeding the others, though
the head of one subsisted at least thirty days.

Thus no undeviating rule is prevalent in determining the circum-
stances incident to the existence of the tubularia, although the necessary
conditions under which the race shall be preserved are governed by gene-
ral laws.

Vigour is indicated by the number and size of the tentacula ; but the
delicacy of the product seems to preclude its preservation until the ruddy
tinge of maturity darkens the original white of the nascent tubularia.

It may be questioned whether, according to the common course of
nature, the fall of the head should precede the expulsion of the foetus from
the cyst. From the evident accessions received by the stalk, indicating reno-
vation of the head, we may certainly conclude that this incident constantly
occurs to the product in its proper abode previous to removal from it.

We collect from the preceding detail, that an external ovarium is
situated among the other parts composing the hydra or head of the Tubu-
laria indivisa ; — that the unusual recurvature of the tentacula, their irre-

TUBULARIA. 13

gularity and symptoms of approaching decay, augment in proportion to its
advancing maturity, while the aspect of the stomach also indicates that its
functions are required no more. It is impossible to overlook the corre-
spondence of these conspicuous facts with that uniform principle of Nature,
obviously testifying a warmer solicitude for perpetuation of the progeny
than for the permanence of the parent. How few are the effectual pro-
visions for warding off a mortal blow from the strongest or the weakest
of animated beings ? How numerous the cares and precautions that others
shall exist ? How infinite are the means of destroying life ! The elements
themselves seem to conspire against it. Mjnriads which have lived perish
in a moment ; while the lapse of time is demanded for their evolution and
maturity, — yet Nature forbids extirpation of their race. Whence is utter
destruction counteracted, and inevitable fate compensated by multiplica-
tion.

The cyst expels its contents as a sphere or an ellipsoid, from which
external organs are about to unfold ; — or their evolution may ensue while
still retained within it. But, the head carrying along with it the whole
ovarium, is likewise observed to separate ; and in falling to dissolve amidst
the circumambient fluid. As all our observations here are restricted of
necessity to the artificial state of the product from confinement, it may
be demanded, which of these alternatives is the natural process ? — Proba-
bly expulsion of the foetus from the ovarium only. There are reasons for
believing it so.

Concomitant decay of the parts being conjoined with progressive ma-
turity of the embryo, did the fall of the head bring down the whole ova-
rium along with it, supervening putrescence might contaminate and consume
the contents in whatever stage. This ensues, indeed, very often in con-
finement ; — the fallen head, together with the ovarium, become a common
mass of corruption. Therefore, expulsion of the nascent being from the
cyst, should precede the fall of the head ; — which seems to be required by
the laws providing for conservation of the race. Whether a second pro-
geny may be then generated in the vacant cyst is unknown. The per-
manence and vigour of the head, however, are perhaps exhausted by the
discharge of the first.

14 ZOOPHYTES.

Yet a new ovarium developes from a regenerated head, if it be suffi-
ciently vigorous ; whence the fall of an old prolific head does not seem to
be accidental but a provision of nature.

Probably the evolution of an ovarium from a regenerated head is re-
strained by the famine suffered in confinement impairing the general
vigour of the subject ; thence it is not common. Nevertheless, examples
do occur, though always on a limited scale. — Plate II. fig. 5. enlarged.
None have ever appeared as ample clusters, or have hung in luxuriance.

The clustering ovaria are generally confined to the largest heads, and
for the most part, March and April may be held the chief season of propa-
gation, though, as common to various other zoophytes, it is not absolutely
excluded from any period of the year. Let the influence of temperature
on organic evolution be kept in view, we shall see that the bottom of the
sea not being subject to the same alternation as the surface of the earth,
nor exposed to similar refrigeration, may account for that incessant gene-
ration and reproduction which seems to suffer little interruption.

The finest ovarium ever occurring to me was in February 1826. On
gross computation, between 200 and 300 cysts were distributed among ten
or eleven clusters, composing it. The head laid on a flat surface spread
like a star, the opposite points of the rays about nine lines asunder. But
the multitude of parts in such limited compass, precluded distinct inspec-
tion of the division and subdivision of the clusters, and the peculiar appro-
priation of the cysts to each ; likewise satisfactory delineation of the whole
was impracticable. In March 1841 and September 1842, clusters of ova-
ria were seen depressing the heads of tubulariae by their weight. Some
heads bore nine clusters, and some clusters had thirty cysts.

Throughout animated nature, there is not a subject better adapted for
profound contemplation, or which can excite greater admiration of man-
kind than the enclosure of a germ susceptible of life and evolution as a
perfect being in an egg. What device alike suitable could have been
contrived as adapting a point — that which has no parts and no magnitude —
to carry on successive generations, accompanying the infinite course of time ?
Let the mind wander over the boundless extent of the animal kingdom ; —
let our sight behold the varied — the endless, the indescribable forms com-

TUBULARIA. 15

prising life — as if exhausting every combination of matter ; astonishment
bewilders our conceptions of the transcendant Power which could fashion
them into definite shapes. It seems as if some ancient world were
shivered, that breath might be infused into every fragment.

Some may ask, indeed, — Could not the attraction, the approximation,
and concurrence of inert particles display the form of living animals by
intimate or reciprocal incorporation ? Could not the vital spark be elicited
by some very simple process, though veiled from mortal eyes ? Life, we
know, is dormant in the originating being ; — matter, we know, is suscep-
tible of its institution there ; — nay, that we can be instrumental in awak-
ening it at will; — that resolving that it shall never glow, the matter
wherein it might have been unfolded perishes irretrievably, or it must
sleep in eternal night.

Yet, what unless design could appropriate the respective parts of
the animal frame, what could guide the vital stream, expand the muscles,
lubricate the joints, or appoint the organs to do their office, such as Nature
requires to be done?

How many theories vanish, how much illusion is refuted and dis-
pelled, in contemplating the perpetuation of the creatures filling the uni-
verse? A definite plan is betrayed, and a regular arrangement for its
execution, which cannot have sprung of simple casualties. The living
world contains in itself the means of replenishing the void of futurity.

Thus the propagation of this humble zoophyte — a subject which of
all others might be presumed the most inexplicable, as the farthest with-
drawn from human notice — is not altogether beyond elucidation. Along
with its birth there was a provision for its permanence.

Let us now resume a few general observations on the reproduction of
defective organs, such as shall replace those necessarily perishing by the
fall and dissolution of the head.

It might be naturally assumed that the summit of a vacant stalk
contains in itself the elements of regenerating parts. But none are truly
there : they reside elsewhere, as we shall easily demonstrate.

In the nascent animal, the stalk vegetates downwards from the disc :
no inferior parts are yet present from which the disc could vegetate up-

16 ZOOPHYTES.

wards. If, in this first instance, the stem descends from the elements of
the disc, or perhaps, in more correctness, from the vicinity of the stomach,
it is probably from the elements of the like originating parts in all sub-
sequent regenerations. This, indeed, is not to be readily understood or
explained, for we always presume the disc as at the highest point, where it
actually appears as sustained on the regenerated neck. But we must con-
ceive what is the earlier stage ; and it will be allowed that the process is
advancing within the tubular stem. The rudiments of the essential organs
are in preparation to unfold before the regenerated mass has rose so high
as to present itself to view. Thence it may be concluded that the whole
evolution is developed from the head as reproductions from the simple
hydra or polypus. This would sanction the presumption that the elemen-
tary organization of all the subsidiary parts resides in what we denominate
the head of the tubularia.

Overpassing the point, however, for the present, we shall .devote a para-
graph to the occurrence, the frequency, the intervals, and the concomi-
tants of so wonderful a property as the renewal of defective parts, one
which seems to retard the stroke of death, and almost to defy mortality.

But the finest, most luxuriant, picturesque, and interesting specimens
are less adapted for protracted observation than those which are meagre
and solitary ; for the latter are neither so ready to spread corruption from .
their exuberance, nor do destructive parasites find a hidden asylum there.
A group of thirteen obtained on March 29, had had three vacant
stalks ; the rest bore heads in various stages. — (PI. II. fig. 1, half size.)
All had fallen on the 31st ; but the ruddy tinge of the three vacant stalks
now announcing speedy reproduction, a head with 22 tentacula issued from
one of them, on the 6th of April, though to enjoy only short existence, as
it fell on the 9th, It was replaced on the 21st, by one with 18 tentacula,
which fell on the 26th. (Fig. 1, g.) The head b, originally with 20 tenta-
cula, flourished April 9, and decaying on the 15th, wasrejjlaced by another
with 20 tentacula also, which fell on the 30th. The heads c and d flou-
rished April 10. The former, on its fall, was replaced on May 4 by a new
head, which fell on the 9th. On the 7th of April e flourished, and it de-
cayed on the 11th. On the 5th, the head/ flourished, and it still subsisted

TUBULARIA. 17

on the 11th. The finest of all flourished on the 7th, and fell on the
15th of April. This group afforded no farther reproductions.

Omitting various subordinate facts, the preceding abstract shows the
absence of all the heads on March 31st ; that six were regenerated against
the 9 th of April ; that two were produced in succession, on 3, c, g ; farther,
that the intervals of their presence and absence were irregular.

Another, a different specimen, flourished on November 21, and the
head fell on December 8. It was succeeded on the 19th by one with 21
tentacula, which fell on the 30th, and was replaced on January 4. by a
head with 20 tentacula, which fell on the 11th. Another head, the fourth,
with 17 tentacula, had regenerated on February 4, and fell on the 8th.
Still a fifth head, with 21 tentacula followed on March 5, proving but
evanescent, for next day it had faded and fallen.

Thus, independently of the heads preceding the first above specified,
which had been indispensable for raising the stem, at that time to the
height of five inches, other five, we see, had flourished in succession, from
the 21st of November until the 6th of March.

The reproduction of six successive heads, from November to April,
on the tallest stalk of a fine specimen was proved in another instance,
though the subject had been much neglected during the interval.

The regenerative faculty of this animal product is very great ; the
latent germ seems ever ready for evolution while the vigour of the stalk
remains.

None of my observations have been sufficiently protracted to deter-
mine its utmost extent.

But is there any vegetable product to rival it in these climates ? Any
one which blossoms and fructifies so often ? We admire their exuberance
if they flourish twice within a year. How infinitely more fertile must
this be deemed, if its most essential organization be renewed repeatedly
within a month ! Should comparison with vegetables fail, let us inquire
whether the lower animals afford a parallel ? I am not aware that any
has been hitherto named.

The germinating powers, however, seem gradually exhausted by repro-
duction ; for the energies required for each evolution are feebler and

VOL. I. c

18 ZOOPHYTES.

feebler, so that frequency represses luxuriance. The succeeding head
never inherits the exuberance of parts and the ample dimensions of its
precursor. The swelling clusters of the ovarium are never regenerated,
nor are they followed by other than simple rudiments, unless in the rarest
instances. Scarcely more than mere ovarian protuberances are repro-
duced in confinement. The extremity of a stalk having been injured about
the 9th of January, after losing its head, subsequent enlargement of long
continuance there was remarkable. At last, a fine new head protruded on
the 9th of March, surpassing the vigour of any regeneration previously ob-
served. Besides 34 or 35 tentacula, regenerated clusters were indicated
in three days, by three rows of protuberances, some of them developing
into bunches of five cysts, before the fall of this new head, which subsisted
nine days. Here the pouch or stomach, guarded by numerous oral palpi,
was much distended. — PL II. fig. 11.

There seems, on the whole, a progressive diminution of the reproduc-
tive energies amidst great irregularity in their exhibition.

Although the earliest animated condition of the tubularia is recognised
under considerable analogy to the hydra proper, its race is not perpetuated
after a similar mode, namely, by external germination ; nor do I know any
of the zoophytes where the polypus or hydra is combined with other parts —
where multiplication by the young issuing immediately from the parent's
body, though often very near it, augments the species.

Pith, or Medullary Matter. — The casual observer may be prone to
conclude that vitality resides throughout every portion of the stem of the
tubularia, because experiment can produce superabundant organization,
that a greater number of essential living parts shall result from artificial
interference than are allotted by nature amidst her undisturbed operations.

The stalk of fine and florid specimens is replete with a yellowish
tenacious mucous matter, completely occupying the whole, or accumulated
in irregular ruddy masses, separated by transparent intervals denoting va-
cuity. Sometimes a surprising discharge issues from the headless summit
above, or from the ruptured root below, when torn off its foundation ; and
sometimes continuing to flow for several days froni either. We know nothing
farther of this substance than that its presence shows the healthy state of

TUBULAEIA. 19

tlie product, and that its absence indicates or prognosticates decay. Though
not putrescent in itself at first, the water is so speedily tainted by it that
the subsequent preservation of specimens needs to be scarcely attempted.

This peculiar substance appears to have an important influence over
life and organization.

If, admitting the evolution of living animals, from an elementary
principle comprising the rudiments of their organs, we find a profound and
difixcult question, — Where is the site of the germ ?

This elementary principle may be conjectured as either of primordial
nature, existing an atom, involved by a series of other atoms, each develop-
ing into sensible form as opportunity admits ; or it may be conjectured to
result from a deposition of matter, secreted from the mature living pro-
duct into some cellular receptacle, whence it shall be subsequently evolved
when in such a state as to be susceptible of attaining an independent con-
dition.

If the germ be lodged amidst the pith, there seems no point through-
out the whole length of the stalk from which it may not be developed,
and that far below the summit, should the portion above be sundered.
Nevertheless, we must guard ourselves from that delusion, where, of a sub-
ject to be so imperfectly discovered, there may be a bud in progress, which
we believe is yet only a germ.

Wherever the germ or the bud be reposited, the presence of the pith
is indispensable for the reproductive process ; and whether the elements of
this process be displayed as internal germination, resulting from secretion
and deposition, on springs of a primordial germ, the principle appears to be
lodged below. That this may be presumed is, first from the new heads of
natural reproduction being observed to rise in the tubular stalk ; secondly,
from the numerous reproductions obtained by artificial sections.

After attaining a certain age and consistence, the elementary prin-
ciple is present of definite size and form in the course of its ascent ; yet,
while still insensible to view, and in some early stage it is susceptible of
injury, of laceration, and partition by an edged instrument, as is proved
by its future evolution, with distorted, multiplied, or superabundant parts.

Supposing the summit of three or four stalks amidst a group to be

20 ZOOPHYTES.

vacant, a head in Tarious stages of advancement in each respectively, will
be seen a little within the orifice. One which thus presented the tip of
the tentacula at noon, protruded part of the disc a few hours later.

The ascent is sometimes speedy, sometimes slow and gradual. The
bud, when near maturity, sometimes appears rather in a spiral form, burst-
ing a transparent delicate spath, as it protrudes from the summit of the
stem. An internal bud of this description, noted as three lines below the
extremity, reached it in three or four days. A nascent tubularia, bred
from the cyst, having lost its head, a new bud was some time afterwards
discovered, at a third of the length of the stalk from the summit. It
flourished through the course of the day following that of observation.

When the continuity of the pith is interrupted, the vacant part of
the stalk becomes of a fine transparent horn colour, which allows the for-
mation of a regenerating head, preparing from the upper portion of the
internal mass of pith below, to be discerned. This aspect being presented
at the distance of an inch from the summit of a stalk, it was sundered
near the place, to facilitate the exit of the reproduction, which could not
have ascended the original vacuity in vigour. Not only did the bud rise
half a line within to the point of this artificial section, but it projected half
a line farther. Nevertheless, it went to decay though florid.

The progressive ascent of the head is demonstrated both by experi-
ment and from exposure by the transparency of the stalk. But it can be
hardly maintained that the germinating principle is universally diffused
amidst the pith, or that the ascent of each regenerating head commences
from the lowest part of the root immediately on privation of the original
organization.

However, several regenerations in different early stages may be ad-
vancing at once.

A new shoot in flourish was deeply wounded, almost to separation of
the parts. Restored to its element, the head had turned round and the
point of adhesion was nearly ruptured. Yet the lacerated parts recovered
their natural position, and their edges having applied together, they seemed
to have united in forty-eight hours. The head which had previously
flourished nine days, fell seventy-two hours after the experiment. The

TUBULARIA. 21

new shoot had elongated nine lines, and the wound had been inflicted six
lines below the disc. Now a slight enlargement became sensible below
the site of the wound. In twenty days a new head, still invested by its
spath or involucrum, though three lines high, was unexpectedly issuing
from the stalk, and burst next day with twenty-two tentacula, its pre-
cursor had only twenty, and it proved a fine specimen.

This regeneration had suffered nothing from the previous wounding of
the stem, either because the minuteness of the germ had eluded the edge
of the instrument, or, which was more probable, because the early bud had
not rose high enough to be injured.

Root. — Little is to be explained regarding the root of the Tubularia.
Its origin seems subordinate to that of the head : it advances downwards,
and extends superficially. But the vegetative principle here, so conspicu-
ous and so vigorous in plants, is apparently much more feeble in this ani-
mal product. Zoophytes, it must be remembered, have no proper pene-
trating or spreading root, comparable to that which is reinforced by acces-
sories in the other kingdom. The root of the Tubularia indivisa runs in a
kind of irregular cylindrical form, somewhat distorted, insomuch, that Ellis
describes the subject as arising " from small worm-like figures, many of
which interwoven together, look like the guts of small animals." He
alludes hereby to the congeries descending from a group, for the root of an
individual specimen is single, appearing simply an opaque yellowish, more
solid and compact prolongation of the stem. Such prolongation is seldom
seen in an artificial state, nor, when it does ensue, is the adhesion alike
firm as in the natural state, where it is very strong. Extension of the
stalk above depends exclusively on the evolution, together with the dura-
tion of the head, for the increment of the one is regulated by the subsis-
tence of the others. But, as far as can be ascertained, its prolongation
downwards is independent of either ; nor is it ever so rapid and evident.
Both the extension and the diameter of the root augment with age as de-
monstrated in older specimens : its course is always superficial, sometimes
descending over the edge of what may sustain it, but scarcely sinking the
least into the surface of shells of softer substance. There is no diffusion
of parts here as with the root of some nascent Sertularice.

22 ZOOPHYTES.

Circulation. — A subject of much interest might admit of some discus-
sion,— ^namely, does any vital fluid, resembling the blood which circulates
throughout the system in the higher order of animals, perform a corres-
ponding function in this race of Zoophytes ?

Here I acknowledge my observations have not been conclusive.
Some authors affirm that they have witnessed currents ascending and de-
scendinsf the stem of the Tubularia indivisa. On no occasion have I been
alike fortunate. I have subjected all different specimens, ages, and parts
to the microscope ; — all different views and positions have been chosen ;
yet I was uniformly unsuccessful. Nascent specimens, still of the palest
grey, almost white, which were more manageable than adults, never af-
forded any evidence of the fact.

Nevertheless, let not these remarks be held as an imputation on the
accuracy or on the veracity of other naturalists, though I have no reason
to believe their vision more acute, or their instruments more perfect than

mine.

Extraordinary embarassment always accompanies the diminution of
light, from the use of such powerful magnifiers as are necessary to bring
very minute objects into view. Thence, although present, they may be
concealed amidst the supervening obscuration.

All that I can say, therefore, concentrates in my inability to discover
circulation in the Tubularia indivisa — reminding the reader that some ob-
servers of no mean note have denied facts advanced by naturalists from
the same cause, which later authorities confirm. One example may be
given in the cilia fringing the tentacula of certain zoophytes.

Having thus briefly disposed of the course of the natural functions
uninterrupted, our attention may be now directed to the results of a few
experiments regarding the nature of this zoophyte, from which physiolo-
gists may possibly draw some deductions subsequently, although presently
appearing matters more of curiosity than use. From these we shall dis-
cover, in the first place, that superabundant organization may be probably
promoted artificially.

Should an animal be seen slumbering in apparent death from priva-
tion of the heart, and if life, motion, and activity were to follow the resto-

TUBULARIA. 23

ration of that important organ, surely it would be a most interesting
question — " Did the heart decay by nature, or was it violently reft from
the carcase ?" The hydra of the zoophyte is to its existence as the heart
in the quadruped.

Effect of Wounds and Lacerations. — A blood-red spot generally re-
mains below the point of separation in the pith, from whence a head has
naturally fallen. But this is not an internal embryo rising to displace the
head ; it seems only a residue of that obtuse prolongation of the disc de-
scending into the stalk, or of the pith itself which had joined the head.
This descending stump, which is inserted for about a line into the stalk, is
sometimes withdrawn entire from the tube as a part of the hydra, then
quitting that sheath as an independent substance. The pith under its
greatest consolidation is very tenacious. A perfect portion extending nine
lines, fell out of a section of the stem after it was sundered ; likewise,
portions entire may be blown out of short sections by the mouth. The
former of vivid red was nearly as solid as flesh ; at least, much more con-
sistent and more tenacious then jelly. Part of the pith seems always to
separate along with the deciduous head.

The regeneration of the ovum in the cyst being void of probability,
and as the fall of the head in our cabinets, without violence, produces the
same nodes or articulations of the stem as are found on specimens with-
drawn from the deep, the elements of a new head to replace the old one
should be preparing on purpose, that perpetuation of the race shall con-
tinue.

Experiment seems to confirm the fact. In the natural state only a
single head can subsist on a stalk. More than one at a time is the result
of monstrous conformation ; nor does this appear once among five hundred
specimens. Indeed, I have never witnessed it above twice or thrice
through a very long series of observations. In the first instance, a much
smaller head issued from the side of a stalk than that crowning the sum-
mit, and about half an inch lower. Another specimen afforded an example
of two stalks, about half an inch long, issuing from a common aperture
still lower in the side of the main stem, and diverging as they rose. —
PI. IV. fig. 25. A third consisted of a stalk, five or six inches high, forking

24 ZOOPHYTES.

into three limbs, all in flourish. The head of the main portion, evidently
the fourth in succession, had 25 tentacula, that of the lowest 22, and the
intermediate head, borne on the shortest stalk, interposed between them,
had 18. These heads, being deciduous, and new heads replacing them,
proved the participation of the whole specimen in the identical nature of
the Tubularia.— PI. IV. fig. 26.

In such cases, the observer must beware of assuming a nascent Tubu-
laria, which evolved from an ovum falling on some neighbouring stalk of
a group, and affixing itself there, thus presents apparent monstrosity.
Here, however, a generating root would betray the truth.

A luxuriant head having fallen from a specimen, the stem, previously
detached from its original site, was now portioned into three sections, the
lowest two inches long, each of those above it one. When entire, the
higher was thrice the diameter of the lower extremity, for it will be
recollected that the stem is smallest at the root. Nothing resulted
from the highest section, where it might have been most expected,
although it was not in decay, and five months afterwards contained
fluid matter, originally the pith. But in ten days a head burst from the
lowest section, where it might have been least expected ; and in fourteen
one from the top of the middle section. Both were flourishing sixteen
days from the date of the experiment, and so continued during a fortnight,
meantime generating as usual a light carnation striated neck, half an inch
long. Thus was superabundant organization obtained, because two heads
cannot naturally subsist at once on the same stalk, nor in the same per-
pendicular line. The lower extremity of these sections adhered to the
side of the vessel, which rarely happens, and both ascended in diagonal
elongation during absence of the heads. Some expectations were indulged
of a head germinating from the lower extremities reddening and becom-
ing very obtuse, which would have been opposite its natural place. But
nothing followed. We shall afterwards find examples of such a generation
among the hydraoid zoophytes.

The preceding experiment proved that the evolution of an elemen-
tary hydra — a germ or embryo two inches down the stalk was promoted
by an artificial section.

TUBULARIA. 25

It does not appear that the embryo ultimately constituting a new
bead displaces its precursor, that its rise and developement are so imme-
mediate as to bring the two in contact.

The distortion and monstrosity consequent on wounds indicate that
the injury is received while the embryo is below ; but the variable and ir-
regular evolution of the parts embarrass our investigation of the original
site of the germinating principle.

In a comparative experiment to ascertain the concomitants of post-
poned evolution, two congeries of intertwisted stalks were cut over.
The one was founded on a stone, the other on a shell. More vigorous
reproduction ensued from the latter, where the section had been twenty-
one lines above the root, than with the former, where within six lines
of it. Conical projections arose from all the stumps, and in thirteen days
a minute head sprouted from one of each congeries. Eight sprung and
flourished ultimately from that on the shell, but the last not until 63 days
after the first, by which time, the stump advancing fastest had regenerated
three heads, and was reddening again — the wonted prognostic of subse-
quent evolution. This congeries is represented as appearing 20 days after
the date of the sections, PI. II. fig. 6, and 67 days later than this figure,
by fig. 10. Its intermediate stages are seen in figs. 7, 8, 9.* The heads
had 12 or 14 tentacula ; they were generally of short duration, the stalks
frequently abortive ; and in about three months from the date of the ex-
periment they ceased to flourish, though again reddening. In eight months
observation was finally abandoned. I now speak of the group upon the
shell remaining after separation of the upper portion of the congeries.

The sundered or upper portion of this same group was found flourish-
ing sixteen days after separation.

As to the congeries on the stone, which consisted of four stalks, after
four vigorous new heads had been generated for the second time, the group
was cut over again three lines lower than the previous section, when, in

* Date of fig. 6, December 22. 1824 ; of figs. 7, 8, 9, January 17, 18, 19, 1825 ; of
fig. 10, February 27. 182.5. Tliis last view is from the side opposite to the view of the
jjreceding figures.

VOL. I. D

26 ZOOPHYTES.

four weeks, other four renovated heads flourished from the mutilated ex-
tremities of the stalks. Vegetation proving languid, the section was re-
peated in a few days, for the third time, and at about the same distance
from the summit, which becomes always higher from prolongation of the
stem by the regenerating heads. The reproduction of four more which
now followed, was accompanied by a fifth very minute, from some stem
previously unobserved, all unfolding successively. Conical projections en-
sued ten weeks after still another section, but the regenerating principle
of farther living organization was exhausted.

By the preceding experiment the prolific elements were found in the
stem descending still lower and lower, and their evolution, though under
great irregularities, was undoubtedly promoted. Low conical projec-
tions rise from sections when placed in an inverted position, as if prognos-
ticating generation, opposite to the natural direction, from the under ex-
tremity, now uppermost, but evolution does not follow.

Ej^dsion. — If deep and unsightly wounds fail to injure the germi-
nating principle, we say it may be so subtile as to elude the edge of the
instrument, or so remote as to be unattainable.

Excisions of the stalk are generally more pernicious than other
lacerations to the reproduction. After them a new head has sometimes
issued from the summit, if vacant. Sometimes, though very seldom, it
issues through the artificial orifice, while all the higher portion has de-
cayed.

It rather appears that the excision being low, the absent head is re-
placed in natural course from the summit ; where high, it may issue through
the aperture.

Five days after an excision three lines below the summit, a small glo-
bular projection issued through the wound, which in two days longer I
discovered, with some surprise, to be a regenerated head bursting its inte-
gument, and it attained sufiicient dimensions. The original head had
fallen previous to the excision. In another experiment, a new head issuing
from an excision made also about three lines from the summit, rent the
stalk by its enlargement. This head fell seven or eight days after pro-
trusion, leaving a shoot half an inch long. In 13 days another flourished

TUBULARIA. 27

in its place for about the same period, but the shoot left by it did not ex-
ceed a line in length. Here the principle, the germ or bud of each, had been
evidently lower than the place of excision.

Of many specimens wounded by excision, two generated monstrosi-
ties in a fortnight, consisting of a double neck, with a head of preternatu-
ral conformation. In one, the reproduction, very florid, never extended
three lines; the other was of similar character, PI. IV. figs. 16, 17. Both
stalks were slender and transparent, thence unfavourable for reproduction ;
nor did these reproductions subsist above three days. One aperture was
less, the other more than half an inch from the top of its stalk.

Six weeks subsequent to the excision of a portion of another stalk, on
March 22, a distorted mass protruded, never developing completely, and
proving on decay, on the 16th of May, to be two papillae terminating a
monstrous shoot. From one of these papilla a small head, somewhat dis-
torted, with about 20 tentacula, burst on November 10. — PI. IV. fig. 18.
Being gradually rounded into shape, it subsisted five or six days : but it
had no successor.

Symmetry restored. — It is no mean presumption that the works of
Nature have been modelled after a given plan, if we behold organic energies
always tending to produce that symmetry which is peculiar to the being
whereon they operate. From the activity of this principle, an original or
an accidental malformation may ultimately attain, or recover its suitable
figure and proportions. A very learned author, Dana, has recently shown
that the form of organized bodies, however complicated, depends on the
vital energies operating on the evolution of the constituent parts.

An incision having penetrated the top of a florid stalk lately va-
cant, regeneration in three weeks exhibited a recurved florid neck covered
by a widely distended globular pouch. A few short distorted tentacula
environed the base, and the summit bore oral palpi of a similar descrip-
tion. This swelling organ, of variable shape according to its nature, was of
a beautiful red colour. Its form subsequently improved by elongation of the
tentacula and diminution of the sphere, but still remaining monstrous, it
decayed in three days. — PL II. fig. 11.

The first head which is generated from a cleft or incision always rises

28 ZOOPHYTES.

in a monstrous fonn, or manifesting peculiarities, if it has not been too
remote, or if its elements have not been too remote to be affected. A sec-
tion an inch and a half long, comprehending the summit of a vacant stalk
that had borne a prolific head, was cleft at both ends on the 11th of Ja^
nuary. A monstrous head was regenerated on the 26th from the upper
end, appearing as in PI. II. fig. 12, on the last of that moilth. It fell on
February 9th or 10th.

From another stalk, also cleft on Januar}^ 11, a symmetrical head had
regenerated on February 11th or 12th. But from a third stalk, cleft at the
same time into unequal parts, two unequal heads were generated on Fe-
bruary 19. The one was sustained on a distorted neck ; the other, not a
fourth or a fifth of its size, had only eight tentacula. The latter outlived
its companion nearly a week. — PI. II. fig. 13. Here I concluded that an
internal bud had been within reach of the instrument.

No definite rules or principles can anticipate the precise course of re-
production.

On November 22, a specimen four or five inches long, with a fine
ovarium, was cut over near the root : and after the head fell the summit
was deeply cleft on the 25th. In 60 days a small head regenerated from
one division of the cleft, and flourished at right angles to the stem. —
PI. IV. fig. 7. It decayed on the fifth day. After a farther interval of 90
days, a florid head with 24 somewhat irregular tentacula regenerated, and,
like the former, at right angles to the stem ; but it rose straighter in a few
days, and on its decay in seven or eight, this was still more obvious. Now
an interval of no less than 143 days elapsed, when a third regeneration
was discovered rising within the stalk in an ovoidal form. It burst as a
head, less obliquely than the two preceding, and it nearly gained perpen-
dicularity, though subsisting but transiently, nor were the tentacula per-
fect. At this time the injury from the cleaving was nearly repaired, for
notwithstanding the previous extraordinary intervals, a fine and flourish-
ing head, the fourth, burst fourteen days after the decay of its precursor.
A thick neck sustained it, but several of its tentacula seemed to be muti-
lated : and on the sixth day it was in a decaying state, much earlier than
its aspect promised. — PL IV. fig. 8. In ten days, however, the embryo of

TUBULARIA. 29

a fifth bead, well defined, was visible within the stalk : the tentacula
were folded longitudinally together ; and the disc denoted by a convex
outline, all the parts being very conspicuous through the delicate inteon-
ment investing them. Next evening the head was displayed with 19 ten-
tacula. It became fine and vigorous ; none of equal dimensions had been
regenerated ; its shape was quite symmetrical, it rose perpendicularly, and
in every thing it proved perfect. The rudiments of an ovarium could be
recognised on the fifth day ; but on the seventh this promising reproduc-
tion separated from the stalk and fell. A very short interval then elapsed,
as on the following evening a new head was bursting from the stalk, which
became fine, and like the last, exhibited 19 tentacula. — PI. IV. fig. 9.
But it flourished only two or three days ; yet the reproductive energies
were not totally exhausted, for the vacant summit reddening again ex-
posed an embryo rising within, which was displayed as a head with 20 ten-
tacula on the 12th of December, and it subsisted ten days. This was the
last organization matured, for although the indications of an embryo ap-
peared a fortnight later, it proved abortive. On supervening transparence
the specimen was abandoned, after remaining the subject of observation
for fifteen months.

It is to be deduced from the preceding experiment, — 1. In the course
of 395 days seven successive heads had been borne by the same specimen
of the tubularia, subsequent to its having attained a high stage of maturity.
2. The interval between the earlier reproductions infinitely exceeded the
ordinary natural period, which is about fourteen days. The first regene-
rated head required 60 days, the second 90 ; and 143 elapsed between the
second and the third. 3. But great irregularity followed, as the fourth
and fifth head required only 14 days each ; the sixth only 9, and the
seventh 31. 4. The first and second reproductions were distorted : the
fifth was perfect. 5. The tendency to symmetry was progressive, and at last
very nearly attained.

The extraordinary intervals requisite for bringing the germ or embryo
to perfection cannot escape notice, no less than 60 days from the date of
the experiment being essential for maturity of the first reo-enerated head •
150 for that of the second, and 293 for that of the third. It is alike sin-

30 ZOOPHYTES.

gular that the intervals then became so much abbreviated, that while 60
days elapsed from the cleaving of the stalk to the evolution of the first re-
generated head, 90 betveeen the fall of the latter and evolution of the
second, and 143 from the fall of the second and evolution of the third, no
more than 14 days were occupied in the regeneration of the fourth.

The embryo is often invisibly sundered in cleaving the stem. Two
vacant stalks, a and 3, were cleft down six and nine lines respectively.
What followed ? In 16 days a head slightly distorted was issuing from a,
the former, and one quite entire in 21 days from b, the latter. Neither
rose from the centre of the stalk ; but they originated individually from
one of the halves of the cleft, about three lines from the extremity. Each
regeneration became free of its half as it grew, and both proved symmetri-
cal ultimately. The head from a had 13 tentacula, that from b had 12.
Each head fell in eleven days. These heads, though on different stalks,
corresponded in position. The first regenerated head of «, adhering to one
side of the cleft, having fallen, another head, somewhat distorted, with
12 tentacula, issued from the opposite side of the cleft, 41 days subsequent
to the original cleaving. It will be recollected that each head first re-
generated had subsisted eleven days. Here the embryo had been undoubt-
edly sundered by the edge of the instrument. One half of the cleft of a
had exhibited a head with 13 tentacula in 16 days ; but the evolution of
what we may conjecture the other half of the sundered embryo was post-
poned during 41 days.

The summit of a stalk having been cleft, on the 14th of February,
two perfect heads were produced on the 3d of March. But the embryo
had not eluded the edge of the instrument ; for, only 12 tentacula being
on one, and 10 on the other, the whole did not exceed the complement
belonging to a single hydra.

The same may be said of the specimen above described, and repre-
sented PI. II. fig 13.

Monstrosities. — If the wound be such as absolutely to preclude the
redintegration of the parts by the sanative energies of Nature, a real mon-
strosity may ensue, and this may appear either in excess or defect. The
subject of monstrosity is deeply interesting to physiologists ; they will ge-

TUBULARIA. 31

nerally find it difficult to understand the cause of supernatural enlarge-
ment, diminution, multiplication, and distortion. Symmetry itself seems to
result from an original harmonious arrangement of the constituent parts
of the elementary organs, and their regular developement following the
institution of life : — deformity from some disturbance received during
the progress of their evolution. But if symmetry be not altogether an
artificial character, expressed by an arbitary term, there is, in truth, for the
most part, throughout the universe, only an approximation towards it.
Regardless of minutiae, when these approximations are close, we hastily pro-
nounce on identity. Still, how seldom is any pair of human organs or
any subordinates of these organs alike ? Amidst a thousand leaves or
flowers we cannot mistake one of any two for the other, on the due exer-
cise of our perceptive faculties. Therefore it would be remarkable, after
the violent divulsion of organic structures, to find its effects totally oblite-
rated by reunion of the parts. Wounds may be inflicted which cannot
heal, spite of the wonderful energies of living matter.

The stalk of a specimen having been cleft down from the summit, no-
thing followed. Afterwards it broke over, but without separating at the
point of fracture, and the cloven summit hung lowest by the side of the
upright stem. There were now two summits, one originally the under
part of the cloven portion, which portion was there inverted, the other the
upper part of the fractured stalk. A hydra issued from each. The sum-
mits were unconnected, but the two hydrae were conjoined by the union of
the oral palpi of the one to the pouch of the other. — PI. II. fig. 14. As
both parts of the ruptured stem were previously upright, the hydra now
issuing from the point opposite to the cleft was opposite to what would
have been its direction by regular and undisturbed reproduction. The
larger and more perfect hydra developed from the main stem in its natu-
ral direction ; the other was inverted. On the 1st of January the rudi-
ments of reproduction were visible from the cleft of a specimen which had
been made a month previously ; and a head veith 14 tentacula, but without
oral palpi, burst on the 7th. The latter developed, however, and the head
become symmetrical, decayed on the 15th. A second head regenerated
from a, the same half of the cleft, on May 3, which fell on the 6th. — PI. IV.

32 ZOOPHYTES.

fig. 19. An enlargement from the other half of the same cleft b, had ap-
peared also on the 1st of January, which burst as a head on the 16th;
fig. 20, b. But from being invested with some mucous matter it scarcely
expanded. No more flourish came of the former cleft a ; however, the
latter, b, generated a symmetrical head, with 14 tentacula, about the 13th
of February ; and this was succeeded by another with 19, on the 13th of
March. But an interval of 167 days now followed its decay, when a very
small head, with parts imperfectly developed, replaced it.

Probably the number, the size, and the distribution of regenerated
organs will depend on the laceration or impunity of the foetus or latent
embryo, or on the obstacles and facilities presented for their evolution.
The peculiar condition of the early subject must expose it more or less to
injury. But it is remarkable that the originating organization of animals
invisible to mankind, and in such a stage of existence should be thus im-
paired, as proved by later increment. Where the head is much smaller,
and only half the wonted number of tentacula belonging to a perfect hydra
border the disc of one or of two regenerated, it is not unreasonable to
conclude that the embryonic product was cleft asunder ; that if the num-
bers be nearly equal it was bisected.

A fine and florid stalk which had borne a prolific hydra was cleft
half an inch down on October 24. Much of the wound healed up as usual ;
but on November 6, a distorted disc, with 30 tentacula, of sufficient di-
mensions, bearing a double pouch, each having its peculiar palpi unfolded,
though imperfectly. Next evening, the neck, originally very stout, had
refined along with the rest into better proportion ; but the heads were
more distorted. — PI. IV. figs. 21, 22, 23, 24. This reproduction subsisted
only another day ; but, in a week, a single head, with 30 short stunted
tentacula, a pouch unusually distended, and very short palpi, rose from the
vacant stalk. Having burst its spath, it decayed without complete evolu-
tion on the day following. In nearly three months it was succeeded by a
new head, somewhat distorted, with about 25 irregular tentacula, which
decayed in three days.

The reproduction, PI. II. fig. 12, was of similar character to the
preceding figures, as above described.

PL. II.

'\

' : f

r ^

<■%

IS

J4

*

^^

T/z/nda/ya ///^///y.sv/ .

TUBULARIA. 33

From the result of these and other experiments, it is evident that the
elements of the future hydra, regenerated on a stalk, do not belong to the
hydra which has come to maturity, but that they reside at some distance
from that summit destined to bear them in their perfect state. Farther,
it is undoubted that their evolution and maturity depend on the presence
of a certain portion of the pith.

I doubt not that skilful physiologists may rear some interesting
theories on the result of experiments proving that reproductions, exceed-
ing the number apparently allotted by nature in her usual course, can be
obtained artificially. Neither will the consequence of protracted inter-
vals be overlooked.

From previous observations it is shown, that seven complete and one
abortive hydra were borne successively in 395 days by a single specimen,
which let us now denominate A, selected originally on November 22. —
PI. IV. figs. 7, 8, 9.

The lower half which is to be denominated B, becoming very foul,
was cut off on the I7th of March following. In 50 days an abortive bul-
bous reproduction rose from the summit of this half. After 131 days
more a head burst on September 11. from the summit, which had reddened
for a long time ; but it decayed next day without complete evolution,
though the neck extended three lines and the tentacula were unfolding.
This last generation from the summit of B had occupied 297 days in at-
taining that degree of maturity, so long having elapsed from the time when
the original stem A, then comprehending B, was cut over near the root
on November 22. of the preceding year. This same last evolution was
succeeded in 40 days by another head, with about 22 tentacula somewhat
distorted and decaying on the second day, from a larger neck than its
precursor. The next, issuing in seven or eight days from the vacant sum-
mit, though subsisting but a single day, was suflflciently symmetrical with
25 tentacula. Its successor, also with 25 tentacula, several of their extre-
mities being mutilated, unfolded on the 11th day, and decayed in four,
after affording a satisfactory delineation. — PL IV. fig. 10. This was fol-
lowed by one in three weeks, still more evanescent, bursting with 25 ten-
tacula on the 5th of November, and decaying on the 6th. The last proved

VOL. I. E

a4 ZOOPHYTES.

of remarkable permanence. It flourished with 17 tentacula on the 7th
of December, and was delineated on the 10th. — Fig. 11. On the 25th
its approaching fall was indicated by separation of the neck from the
internal pith of the stalk, after which, vacuities and transparency prov-
ing the exhaustion of the reproductive principle, farther observation on
this section B was abandoned on January 15. or in very nearly one year
and two months from the 22d of November.

The heads obtained by this experiment from the section B, originally
the lower half of the stalk A, were seven.

As the energies above of the section B had ceased, an inch and a half,
C was sundered from its lower extremity.

Thus the original stem, first sundered on November 22. had been now

, sundered into three portions. A, B, C, of which the intervals follow. A

was sundered 22d November ; B cut off it in 84 days, and C cut off B

333 days afterwards. Therefore the separation of C was 417 days after

the portion B B had been originally removed.

This last section, C, being laid horizontally at the bottom of a narrow
cylindrical vessel, a head with 19 tentacula rose at right angles from it in
the subsequent February, within a month of the division. — PI. IV. fig. 14.
It fell on the 25th of the same month, when an embryo next ascending
the stalk decayed on March 13. without evolution. Howsoever, a head
with 25 tentacula developed on the 9th of April, and subsisted three days.
Now, the new shoot extending an inch and a half, produced a vigorous
head with 20 tentacula on May 24. which fell on the 3d of June. — PL IV.
fig. 15. Supervening transparence induced me to abandon this section C
on the first of October, after having generated three heads and one em-
bryo, as above specified.

But a remarkable incident had followed the separation of C, fig. 14,
from B, figs. 10, 11, of which figures it was the lower portion. The sum-
mit of B, fig. 12, was vacant at a, when C, fig. 14, was separated from it ;
and the headless portion consisted oi ah only. Nearly three weeks after-
wards a shoot bearing a hydra, c, was generated from b, the lower extre-
mity of B, and on February 11. was rising upwards by a very regular cur-
vature. B had been suspended by a silk thread in a jar of sea-water.

TUBULARIA. 35

This reproduction, c, subsisted until February 25. Another head, with 20
tentacula, replaced it on March 5. and decayed in three days. A third, also
with 20 tentacula, was reproduced on March 20. and decayed within the
same period ; and a fourth, lasting as long, burst with 19 tentacula on the
12th of May. The shoot now extended an inch and three quarters, its
ruddy tinge gradually faded, when its regeneration ceased. — PI. IV. fig. 13.

Relative to the latter experiment, it is worthy of observation, that
sundering C from B had generated two heads at what was the point of in-
tersection of fig. 11, which figure represents B C entire, as composed of
figs. 12, 14 ; for, one head vegetated naturally from the higher extremity of
C, fig. 14, while another vegetated unnaturally, fig. 12 c, from the point b,
whence it had been sundered. These two heads vegetating by ascent and
descent, from what had been the same point, flourished at the same time,
February 16. and fell at the same time, on the 25th. Both had attained
sufficient dimensions ; the rudiments of an ovarium became perceptible in
one, which was, besides, very tenacious of life, as it survived its fall eleven
days. But that from ascent having 19, and that from descent 18 tenta-
cula, it may be conjectured, that although so very remote from the natural
site of evolution, the summit of both had originally constituted a single
embryo, which, by partition, developed into two, becoming progressively
symmetrical in maturity.

Thus, while A had naturally afforded seven perfect hydrse, besides an
embryo, B had generated seven by ascent, and four by descent, and from C,
three together with an embryo had ascended.

Therefore, in the course of 550 days, the single specimen rendered in
this manner the subject of experiment, had borne 22 heads, including that
subsisting when it was withdrawn from the sea.

By cleaving a fine stalk D, on November 25, some farther illustra-
tions were obtained of the preceding facts. From this, the head, with an
ovarium, had already fallen. The wound healed, and in 56 days, a head
for some time standing awry, but afterwards gaining symmetry, burst with
25 tentacula. — PL IV. fig. 1. It fell in eight days. Another flourished
and decayed. Then a third with 21 tentacula, not inferior to the first. It
now rose vertically.

36 ZOOPHYTES.

A portion E, being the lower part of D, was severed from it on the
17th of March following. The summit of this portion E, though afford-
ing symptoms of reproduction, generated no symmetrical head, until one
with 21 tentacula appeared on the 12th of October, and decayed in three
days. — PI. IV. fig. 2. Another head, being the third, quite symmetrical,
vigorous, and florid, with the same number of tentacula, succeeded it.
But the fourth was slightly distorted. A fifth was generated on the 8th
of December, and subsisted until the 17th. — PI. IV. fig. 4.

Symptoms of internal decay at this time interrupting reproduction, it
was seen as represented, fig. 4.

About 18 lines, F, were severed from the lower part of E, and con-
signed to a narrow glass cylinder, on January 4. after the preceding De-
cember. On February 11. a vigorous hydra, with 19 tentacula, had de-
veloped, and was then some days old. But, cramped for room, it had
turned upwards, as the section itself lay horizontally, fig. 5. Having sub-
sisted above a fortnight, it was succeeded by another with an equal num-
ber of tentacula, which burst on March 6. and fell in three days. The
section being now suspended in a more capacious vessel, its increment un-
restrained, made rapid advances with a third hydra, which subsisted four-
teen days from April 12. At this time the length of the new shoot
equalled the length. of the original section, and it had become nearly ver-
tical.—PL IV. fig. 6.

Supervening transparence in June rendered farther observations un-
necessary. The total hydrse regenerated by this stalk and its sections in
506 days amounted to twelve in number.

The following conclusions may be deduced from the preceding nar-
rative : —

I. — ^The Tuhularia Indivisa consists of a single living hydra, sustained
on a fistulous stem, rooted irreversibly to a solid foundation.

II. — The stem is occupied by a tenacious matter or pith, essential to
the permanent life and the animal functions of the product.

III. — An external ovarium, composed of several clusters, is borne by
the hydra, each cluster consisting of several cysts, and each cyst contain-
ing an ovum or embryo.

PL. 111.

7

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>

SL

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TUBULARIA. 37

IV. — On expulsion of the ovum from the cyst a hydra is unfolded,
which enjoys the faculty of locomotion, and in its earlier stages evinces
animal nature exclusively.

V. — After a brief display of the locomotive faculty, the hydra becomes
rooted permanently, and thus it flourishes, enlarges, multiplies, and dies.

VI. — ^The original hydra reared on the first elongated stem falls from
its summit, after a certain but indefinite interval from its evolution, and
perishes below.

VII. — One or more hydrse, according to the vigour of the specimen,
replace in succession that which has first fallen.

VIII. — If the luxuriance of the hydra be great when the subject is
originally recovered from the sea, that of its successor is generally inferior.

IX. — No correspondence appears between the dimensions and the
number of regenerated organs of the successor, and those of its immediate
precursor.

X. — No uniform length of interval prevails between the regeneration
of the successive hydrae, some being evolved much more speedily than
others.

XI. — No uniform duration prevails among the regenerated hydrae.

XII. — Prolongation of the stem is absolutely dependent on the exist-
ence of the hydra, and the rate of increment generally corresponds to its
duration.

XIII. — Six successive hydra may be generated from the summit of
the same stem in six months.

XIV. — ^The germ or elements of each hydra probably reside at some
distance from the summit of the stem.

XV. — A greater number of hydrae than apparently allotted by nature
to a single stem, may be obtained by artificial sections or subdivisions of it.

XVI. — By such subdivisions, 22 hydrae have been generated in 550
days from three sections of a single stem.

XVII. — Monstrosities from external injury to succeeding hydrae be-
fore evolution are gradually effaced in each successor ; and symmetry, to
which there appears a constant tendency, is restored, in remote regenera-
tions.

38 ZOOPHYTES.

Contemplating this humble and defenceless production of Nature,
how many admirable properties does it not disclose ? It blossoms as a
beautiful plant in the dark abysses of the deep. The offspring generated
in the head of the parent drops from its place, to unfold its organs, and
to enjoy an independent existence. Though endowed with the privilege
of moving around to select its site, no sooner does it show its choice,
than there it is appointed to rest for ever. The fruit of its prolific womb
discharged, the head which bears it is sundered, and the extinction me-
naced of its reproductive powers. But Nature interposes for their pre-
servation. Another head is generated. Another ovarium may be borne.
The means of providing for posterity ensure conservation of the race.
Dwelling amidst the ravenous tenants of the deep, the delicate organs of
this defenceless being are offered for immediate prey. What if torn asun-
der, mutilated, or severed into many parts ? It may arise as yet un-
hurt. Wounds and lacerations — such as are mortal to the strongest in-
habitants of the earth — have not impaired its vital principle ; and that
important portion bearing the source of distant generations, is renovated,
to flourish in all its pristine symmetry.

Plate I. — General view of a group of the Tuhtdaria Indivisa, founded on
a mussel shell, a large portion being invested by parasite matter.

Plate II. — Renovation and propagation of the Tuhidaria Indivisa.

Fig. 1 . Group illustrating the deciduous nature of the hydra, reduced to
half the size of life.

2. Prolific hydra.

3. Prolific hydra, front.

4. The same viewed from behind.

5. Eegenerated hydra, with incipient ovarium.

6. Group of regenerating hydrse, after separation of the upper por-

tion, as appearing December 22.

7. The same as appearing subsequently, January 14.

8. The same, January 17.

9. The same, January 18.

TUBULARIA. 39

Fig. 10. The same as appearing subsequently, February 27.

11. Monstrous reproduction of a head, afterwards becoming symme-

trical.

12. Monstrous reproduction from a cleft stalk.

13. Monstrous reproduction from a cleft.

14. Monstrous reproduction from a stalk fractured.

15. Group of uncertain species — supposed the Tubularia Larynx.

Plate III. — Propagation of the Tubularia Indivisa.

Fig. 1. Prolific hydra, being one of the group Plate I., with an ovarium
consisting of several clusters of cysts, each containing an ovum
or an embryo. — Tentacula, a, oral palpi, h. Slightly larger
than life.

2. Cluster of cysts.

3. The same enlarged.

4. Cluster of cysts.

5. The same enlarged.

6. Cluster of cysts in different stages, h.

7. The same enlarged.

8. Cluster of cysts less mature.

9. Cluster of cysts, where the embryo is exposed through the semi-

transparent sac, enlarged.

10. Cyst expelling its ovum or embryo, enlarged.

11. Another.

12. Another.

13. The same, — the embryo, i, having been expelled from the cyst, a,

enlarged.

14. Ova or embryos after expulsion, enlarged.

15. Ova or embryos, of irregular size and shape, enlarged.

16. Cluster of cysts wherein the contents are unequally advanced. —

The tentaculum, a, of an embryo protruding from a cyst, b, en-
larged.

17. Tentacula of an embryo farther advanced, protruding from a cyst,

enlarged.

18. Cluster of cysts unequally advanced, several tentacula, a, protrud-

ing from their cyst, S, enlarged.

19. Tentacula, a, from an embryo still farther advanced in the cyst,

J, before expulsion, enlarged.

40 ZOOPHYTES.

Fig. 20. Hydra in an early stage, developing in a stellate form from its
embryo state; enlarged.

21. Nascent Tubularia, — tentacula still clavate, enlarged.

22. Nascent Tubularia farther advanced, — oral palpi, a, originating,

enlarged.

23. Nascent Tubularia, — the tentacula nearly symmetrical, front, en-

larged.

24. Nascent Tubularia, sustained on the tentacula, — oral palpi un-

folding, enlarged.

25. Nascent Tubularia, still free, — organs almost symmetrical.

26. The same enlarged.

27-34. The figures inclusive represent young Tubularise bred from the
cyst, in January 1841, in various positions, all rooted.

35. Young Tubularia (fig. 28 enlarged), with irregularities near the

root.

36. Young Tubularia bred from the cyst.

37. Another.

38. Young Tubularia bred from a cyst of fig. 18.

89. Young Tubularia bred with 15 tentacula from the cyst. The ten-
tacula of the regenerated hydra succeeding it were only 7.

40. Young Tubularia bred from the cyst in 1832. The hydra sub-

sisted 21 days.

41. Upper portion of a young Tubularia, with a renovated hydra,

which is rising from the stem.

42. Young Tubularia bred from the cyst, enlarged.

43. Prolific Tubularia — natural eize.

Plate IV. — Redintegrations of the Tubularia Indivisa.

Fig. 1. A hydra or head generated from an artificial cleft.

2. The original stalk of fig. 1, having been previously cut asunder,

the hydra of this fig. 2, was generated from the summit of the
lower half.

3. Head generated from the same lower half, after fig. 2 fell.

4. Summit of the regenerated neck in decay.

5. The lower half of fig. 2 having been sundered, a hydra was gene-

rated from the summit of this section.

6. Another hydra, generated from the same summit of fig. 5, in suc-

cession to the former, the shoot having prolonged.

/■/,. /I'.

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Tnhii/mifi Jnffi\ f

TUBULARIA. 41

Fig. 7. A hydra, generated at right angles to the stem, from an artificial
cleft of a different specimen — none of the preceding.

8. Another hydra, generated from the same cleft, after the former

feU.

9. A third hydra, generated from the same cleft, the parts originally

distorted, having now become sjonmetrical.

1 0. Hydra, generated from the lower half of fig. 7, which had been

sundered.

11. Hydra, generated in succession to fig. 10, from the summit of the

same lower section.

12. This figure, originally the lower section of fig. 7, remained the

upper part of fig. 10, after this fig. 10. lost its own lower half.
The vacant summit a had borne the hydra of fig. 11, and now
when that hydra had fallen, a hydra c sprung from the oppo-
site or lower extremity, contrary to the course of nature, and
then gradually rose upwards.

13. Ultimate appearance of fig. 12, in decay, after losing the hydra

from c.

1 4. Hydra, generated in the natural direction, from the lower half of

fig. 10.

15. Second hydra, succeeding fig. 14.

1 6. Monstrous hydra, issuing through an excision of a part of a stalk.

17. Monstrous hydra, issuing through an excision of the stalk of an-

other specimen.
IS. Monstrous hydra, issuing from an excision of a third stalk.

19. Reproduction from a cleft stalk — hydra displayed — hydra in em-

bryo 5.

20. The same, a, having decayed, and 5 having unfolded.

21. A stalk cleft, October 24.

22. The same, with an obscure embryonic formation, November 4.

23. The same, with the preceding formation developed as a monstrous

hydra, November 6.

24. The same, as appearing November 7.

25. A stalk, apparently monstrous by nature.

26. Another stalk, apparently monstrous by nature.

VOT„ I.

42 ZOOPHYTES.

2. TuBULARiA LARYNX.* — Plate V. — The preceding disquisition,
prolix, no doubt, to those impatient for conclusions, will enable us to ab-
breviate the history of this singular genus, for all participate of a common
nature, though exhibited under conspicuous modifications.

The larger organic bodies afford the observer many enviable facilities,
compared with the series of those animated beings, vanishing by progres-
sive diminution from his view.

The simplicity distinguishing the preceding product recommends it as
a suitable introduction to the knowledge of its more complex and more
diminutive kindred. Its external parts are few : the root a mere prolon-
gation of the stem, which latter, never dividing, is always single ; its di-
mensions are readily exposed to the naked eye, or they may be compassed
by moderate magnifiers. Farther, it is not of diflScult preservation. But
others, most minute, are of obscure and intricate formation, whether col-
lectively, when dwelling in society, or individually, if existing in a solitary
state. Thence they require separation, division, and a kind of analysis in
pursuing the investigation of their nature.

Like the former, the Tubular ia larynjc is found either in a social or
a solitary state.

In the month of December a group was recovered from the sea, re-
sembling a copious handful of white, crisp, baked horse hair, which rose
two inches high, and occupied a vessel of four inches diameter.

Closer inspection discovered this to be a vast congeries ; — one of not
fewer than five hundred snowy tubes, crowned by scarlet animated^ blos-
soms of various hue. In the aggregate, it may be conipared to a fine and
beautiful tuft of pinks decorating a flower-garden. — Plate V. fig. 1.

Viewed externally, it seemed doubtftd whether this luxuriant assem-
blage sprung from a single root or from many, the whole being some-
what contracted by convergence below. But one alike numerous is of rare

* This name has been applied from the whirls or prominent rings sometimes on parts
of the stalks as resembling the windpipe. It is not warranted by such being a distinct and
invariable character. The whirls or convexities are the converse of the hollow circumfer-
ence of pulleys.

TUBULARIA. 43

occurrence ; the product commonly appears as a parasite on other zoo-
phytes, seldom on shells, rocks, or stones.

The Tubidaria larynx rises three inches high ; it consists of a stem,
subdividing into several irregular ramifications, each crowned by a hydra,
narrowly resembling that of the Tiihularia indivisa in structure and ap-
pearance. All the tubular parts are white, the hydra red. The former,
that is the tube, occurs from the diameter of a horse's hair to the third or
fourth of a line ; and the latter from a mere speck to three lines in expan-
sion between the opposite tips of the tentacula. About 21 tentacula bor-
der the disc of the finest specimens ; the mouth is fringed by about 16
palpi, rough, rounder, and more obtuse than those of the Tuhularia indi-
visa. Faint whirls indent the neck of some specimens, and two of the
ramifications are sometimes united by a cross bar.

Much irregularity subsists in aspect and proportions. Specimens
occur of all inferior dimensions to the largest instanced above, and of great
discrepancy in the proportion and number of parts. Specks scarcely
discernible by the naked eye are nearly white ; and others of very minute
dimensions which have only nine, or even but six tentacula. A stalk an
inch long frequently bears a head no larger than a branch extending three
lines from its side. Thus no definite rules seem applicable to the size,
proportions and appearance of this product. The lower parts are also
always so much interwoven, that, until cut out from among the rest, it is
impossible to determine the formation of a single specimen : Nor is it
easy to discover that only a single root is extricated. But the general
aspect and structure of the Tubularia may be seen in figs. 2, 3, 4.

The polypus or hydra is not retractile within the stem, as there is no
vacuity in the summit for its reception. It is of a more lively nature than
the former, turning freely from side to side, closing and unfolding itself
repeatedly, and apparently enjoying a moderate degree of light. But both
are of that languid inactive disposition which constitutes a prominent fea-
ture of most zoophytes void of a receptacle for retreat and protection of
the head on the occurrence of danger. — Figs. 5, 6, enlarged.

The propagation of this Tubularia resembles that of the indivisa in as
far as it can be ascertained. But the precise process is very rarely wit-

44 ZOOPHYTES.

nessed. Like the former, clusters of minute cysts are borne on the head,
from which embryos have been obtained in the month of June. The
nascent animal is originally white, or of the palest grey — figs. 7, 8. It is
so difficult to be obtained, however, that eleven years from the commence-
ment of my original observations elapsed before I could procure prolific
specimens. The naturalist is compelled to rely on accident as much as on
design for the success of his objects.

The evolution, decay, and disappearance of the head form another
illustration of the vigorous reproductive faculty residing in the genus.
Here the progressive renewal is more conspicuous than in the preceding,
from the readier exposure of the rising embryo, and its stronger contrast
with the thin sides of the tubular stem.

The hydra is deciduous. It survives its fall entire during a certain
time, and the summit of the stalk remains vacant. But a florid internal
bud is soon discovered ascending towards the extremity of its sno^vy cylin-
der, whence it speedily bursts ; and sometimes the progress is so rapid
that on one occasion it issued forth and spread, during the course of a
single protracted observation.

In this respect, the Tubidnria larynw probably exceeds the regenera-
tions of the indiirim. The limits confining the renovation of these, the
parts most essential to life and the perpetuation of its race, cannot be de-
fined.

On April 14, two single specimens were selected for observation —
one with eight hydrae, besides several vacant stalks, fig. 2 ; the other with
five hydrse and two vacant stalks, or seven summits in all, fig. 3.

The vacant stalks had flourished recently. Vigorous reproduction
now ensued, but attended with much irregularity, both in respect to matu-
rity and to its duration, as well as in the number of regenerated organs.

The specimen, fig. 2, had eight hydrae on the 14th of April, at which
time a was vacant. Here a hydra was regenerated on the 20th, which had
fallen on the 25th. This hydra was reproduced. I should rather more
correctly say, it was succeeded by another next day, the 26th. The last
had fallen May 1 ; it was regenerated on the 7th, by one which had fallen
on the 12th. Another, regenerated on the 18th, had fallen on the 25th ;

TUBULARIA. 45

it was regenerated on the 28th, and decayed on the 30th, but still a new
hydra, on June 8th, replaced it, which fell on the 10th. Thus six hydrte
regenerated from the same stalk in 51 or 52 days.

The hydra, fig. 2, h, was displayed April 14. It had fallen May 7,
and was regenerated on the 12th. But no reproduction followed this suc-
cessor.

The hydra, fig. 2, c, was also displayed on 14th April, and fell on the
20th, without farther reproduction. Therefore, the former, b, regenerated
only two heads, and the latter but one.

Although the whole stalks of this specimen, fig. 2, were prolific, it
never bore above eight hydrae at once, subsequent to the commencement of
their fall.

On May 2. all the stalks were vacant : in five days the specimen had
seven heads.

The specimen fig. 3, was totally vacant on May 2 ; and after various
reproductions, it was totally vacant again on May 14. The number of co-
temporary hydriB after they began to fall never exceeded three. The
hydra c, of this specimen, flourishing April 19. fell and was regenerated
for the fifth time, including preceding regenerations, on May 31 ; that is,
in 42 days. Progressive reduction of the number of reproduced organs is
proportional to the frequency of regeneration here, as in the Tubularla
iiidivisa.

The hydra c had 14 tentacula on the third regeneration ; on the fifth
it had only 12.

The same peculiarity has been evinced still more conspicuously in
other examples. Thus, the hydra fig. 2, ?, falling April 20, was replaced
on the 23d, by a fine head with 16 tentacula. This falling on the 28th,
was succeeded by one with 12 tentacula, on May 3. The latter had
fallen on the 9th of May, and it was renewed with 10 tentacula on the
12th. Having fallen, it was regenerated with 9 tentacula on the 28th.
This having fallen, a new hydra appeared next day, June 4. with only
seven ; which, on its fall, was replaced by yet another hydra, with no more
than six tentacula. The successive heads actually seen and enumerated
amounted to seven, all being in existence and inheriting the. summit of a

46 ZOOPHYTES.

single stalk after each other, within 66 days. The complement of tenta-
cula crowning the first was accidentally overlooked. Probably it ex-
ceeded that of the second, which was regenerated with 16 ; while the
seventh head had only six. The meagreness of its aspect was extraordi-
nary.

The hydra fig. 2, d, having fallen April 18. another with 18 tentacula
was generated on the 22d. Its successor, on May 13. had only 10 ; this
was replaced on the 30th ; it fell, and was succeeded on June 10. by one
having 8. But the next and last, which was scarcely visible, had only

7.— PI. V. fig. 9.

Thus, in the Tubularia larynoc, degeneration of the hydra is conco-
mitant on reproduction.

In general this portion of the organization subsists five or six days.
The intervals of reproduction are quite indefinite ; sometimes, though very
seldom, a day or two intervenes between the disappearance of the old
hydra and the evolution of the new one ; sometimes from three to eight.
For the most part the stalk remains vacant for about five days.

The finest regeneration commonly issues from the largest stalk.

At first the new head is very minute : the heads of shorter stalks are
particularly so, and they are very pale : several have been scarcely percep-
tible, and the neck is extremely slender. Like the parts of the Tubularia
indivisa, both enlarge in time. The neck is prolonged also during sub-
sistence of its head, whence, by the accession of no more than the third
of a line at once, a specimen reproducing profusely, gains considerable
comparative altitude by the aggregate accessions.

This, however, is ultimately productive of much inconvenience to the
observer, for the longer parts above and the shorter below, preserving no
regular or definite direction, they are respectively intercepted from the
eye, or interrupt the view of earlier reproductions. Thus, in the course of
June, the specimens figs. 2, 3, had become so intricate, by prolongations
and curvatures of the stalks ; and the hydrse had become so minute in re-
peated regeneration, that farther observations on them could not be satis-
factorily continued.

The regenerative qualities of this product are very powerful, as it is

TUBULARIA. 47

seen from the preceding detail, that seven hydrse subsisted in 66 days ;
that their average duration, including the interval of their absence, scarcely
exceeded nine days ; — that a new head might even unfold and occupy the
place of one which had been in existence the preceding day.

The progressive degeneration of external organs, whether in size or
number, is no less remarkable, — as if evincing the gradual exhaustion of
the resources or energies of nature. Contrasting the fine, florid, and luxu-
riant hydra with 22 tentacula, and some remote successor, pale and di-
minutive, with only 6 or 7, proves the difference between feeble and vigo-
rous evolution.

In probing the embryonic sources, a subject of such profound interest
to the philosopher, arguments might be reared against the infinite evolu-
tion of germs, from the nature of the reproductions of the two species of
Tubularia now described. Some might certainly maintain that were such
the primitive order, all the germs would unfold the true complement of
organs, distinguishing its peculiar kind, though of diminished size. But
if the germ be generated immediately in the parent, it might be said that
the production of animals in such rapid succession impairs the quantum of
elementary matter to be derived for each, which shall suffice for the
nucleus of the offspring, — whence the organization of the successive hydrae
degenerates Likewise, some may conclude that the primitive or succes-
sive germs are not all reposited in a magazine of vitality, seated amidst
the pith or elsewhere deep in the stem, but that the embryo may be gene-
rated from the internal surface of the fistulous tube below, or foi-med in
some invisible cell, by the organic energies of the parent.

If we admit the universal vascular structure of the elementary parts
of animal matter, the theory of primitive germs is supported, because the
dilatability and increment of the parts, resulting from the institution of
life and consequent nutrition, may adapt them for the benefit of the per-
fect being.

Perhaps there are varieties of this and the subject of the next chap-
ter, which perplex the observer in determining on rejecting identity. The
want of absolute uniformity which pervades all animated objects, and of
which we become sensible as we are more or less acquainted with them, can-

48 ZOOPHYTES.

not but excite doubts and difficulties : Nor can we tell what tests are
authoritative. Degeneration itself alters the appearance of specimens so
much, that it is scarcely possible to class them with the more vigorous of
the race. Yet degeneration does not merely result from that exhaustion
of the elements of evolution which seems concomitant on successive repro-
duction. But, as an unsuitable soil and climate reduce gigantic vegeta-
table products to dwarfs, or absolutely preclude their germination, so is
the growth of all zoophytes repressed by an unfavourable position. Some
of the more prominent features distinguishing certain species may be thus
obliterated. Without a profusion of specimens, our doubts cannot be re-
solved, and such specimens must be of that description, besides, as to ad-
vance from greater imperfection to superior quality.

A group of about 20 specimens vegetated through some spongy mat-
ter wherein the roots were involved. No whirls distinguished any por-
tion of the stalk ; but the course of reproduction was infinitely quicker
than in the Tuhularia indivisa, and the hydrae had all the characters of
the larynx. None of the stalks were connected by bars. Unless for
the speedy reproduction, these might have been thought dwarf indivisa.
—PL II. fig. 15.

The Tuhularia larynx is infested by dangerous enemies. During
the frequent regenerations of the fine and ample specimen first described,
a very numerous colony of a certain kind of Doris, which shall come under
cognizance in its proper place, menaced its destruction. These little crea-
tures, also consuming the epidermis of the Tuhularia indivisa, now nestled
among the most intricate recesses of the mass, whence they could not be
otherwise dislodged than by a slight putrescence imparted to the water,
compelling them to forsake their haunts below in quest of a purer me-
dium. Thus were 68 diminutive parasites captured and removed. Re-
peated lotions cleansed and purified the tuft, so that regeneration con-
tinued. But the ravages of the Doris had been great, and clusters of its
spawn remained inaccessible.

V I

PL I'

■3

.t

c^lH^

*

hT" h/^'^

7

Titfi ll/ftt lifZtffl/7lX

TUBULARIA. 49

Plate V. Fig. 1. Tuhularia Zarywa;— Compound or many headed Tubularia ;
Group.

2. Specimen selected for illustrating the course of reproduction.

3. Another, selected for the same purpose. The pecuhar aspect

of the product is shewn by both.

4. Skeleton of fig. 2, shewing the structure of the inorganic parts.

5. Hydra and Stalk, tentacula a.

6. Hydra and Stalk.

7. Nascent Tubularia from the ovum.

8. Another.

9. Regenerated hydra, shewing the progressive diminution of the

organs.
All the preceding, except fig. 1, enlarged.

VOL I.

50 ZOOPHYTES.

CHAPTER II.

TuBULARiA (Sertularia) Ramea. — Plates VI. VII. VIII. IX. X.

^ § 1. The Tubularia proper is distinguished by two prominent charac-
teristics ;^r5/, In the hydra having a double row of tentacula ; second, In an
ovarium of pendent clusters, near the stomach, being interposed between
them. I have found none in Scotland, unless the two preceding species,
with similar organs thus disposed. As neither of these features, palpi or
clusters, is presented by the subject of this paragraph, it ought certainly to
be incorporated with the SertularicB, or perhaps assigned to an interme-
diate place.

Some recent authorities, indeed, propose to denominate it Euden-
drium, which is rather more adapted for a specific than a generic distinc-
tion, especially from being inappropriate to nine-tenths of the specimens
occurring, and in applying with equal force to many other zoophjiies.

The hydra seems precisely of the same structure and habits as that
of the Sertularia. It propagates, with exception of some peculiarities,
precisely after an analogous fashion, through the medium of a prolific pod
or vesicle ; the progeny issuing from this most narrowly resembles the
planula, which we shall see is discharged by the other, insomuch that for
facility of indication they may pass by the same name.

Here, however, no cavity terminates the extremities of the product,
adapted for reception of the numerous hydrse; there are neither the cylinders,
sheaths, nor bells of most Sertularia; ; and they can only contract, instead of
enjoying the privilege of retreating. But this important safeguard is not
only incomplete in various species of the Sertularian tribes, but, when na-
turalists have even founded the systematic name and arrangement on its

TUBULARIA. 51

presence in others, it is transient, and in some perishing with the tenant,
though regenerated along with a successor.

The subject of this paragraph is therefore more nearly allied to the
Sertularia than to the Tubularia, or to any other established genus. But
while retaining the name, to avoid the perplexities involved by injudicious
changes, I shall leave it to the skilful framer of the Systema to settle its
true position.

This is a splendid animal production — one of the most singular, beau-
tiful, and interesting among the boundless works of Nature. Sometimes
it resembles an aged tree, blighted amidst the war of the elements, or
withered by the deep corrosions of time ; sometimes it resembles a vigo-
rous flowering shrub in miniature, rising with a dark brown stem, and di-
verging into numerous boughs, branches, and twigs, terminating in so
many hydrae, wherein red and yellow intermixed afford a fine contrast to
the whole.— Plate VI. VII. X.

The glowing colours of the one and the venerable aspect of the other,
their intricate parts, often laden with prolific fruit, and their numberless
tenants, all highly picturesque, are equally calculated to attract our admi-
ration to the creative power displayed throughout the universe, and to
sanction the character of this product as one of uncommon interest and
beauty.

But from its appearing in infinite variety, and as it is shown from the
different synonyms bestowed that they cannot be uniformly applicable to
any one subject as a type of the rest, and as many doubts may remain
when they are concentrated under review, it is necessary to enter into a
more special detail. Nothing is readier to delude the naturalist than
beholding the earliest and the latest stages of such products, if deprived of
intermediate specimens to explain their progress and transition.

A very fine specimen of the Tubularia Ramea was recovered from
among the rocks of a cavity in the bottom of the Firth of Forth, at about
150 feet from the surface. It had vegetated in such a direction, that it
was detached quite entire.

Being transferred to a capacious vessel of sea-water, I found this Tu-
bularia rising seven inches and a half in height, by a stem about nine lines

52 ZOOPHYTES.

in diameter near the root, then subdividing into several massy boughs,
besides many lesser branches.

Numberless twigs, terminated by thousands of minute hydrae of the
palest carnation, clothed the extremities which were ten inches apart.

The root itself diffused irregularly by a multitude of mossy-like fibres,
which might be circumscribed by a circle of two inches diameter. It is to be
observed that the stem and the higher rigid portions consisted of irregular
bundles of tubes ; but about two inches of the highest were in verticillate
arrangement, that is, composed of twigs, set around the leading part, and
not in simple divergence to right and left from it.* Though composed of
bundles of tubes below, the absolute extremities bearing the hydrae resolve
into single tubes, each with its animal.

Many parasites invested this splendid specimen. Masses of the pure
white and deep orange Alcyonium digitatum or Lobularia hung from the
boughs ; Sertulurice, sponges, and Algce, were profusely interspersed, all
proving, by their obvious successive generations, the great antiquity of the
Tubularia.

A fine and accurate representation of the specimen was speedily
executed by a masterly artist, Mr John Welch, miniature-painter. Yet,
such was the extraordinary luxuriance of this product, that an infinity of
subordinate parts were delightful to the eye in nature, which, intercepted
by others, could not be shown on a mere surface. — Plate VI.

So great an accumulation of parasite matter, however, combined with
animal life, hastened the decay of this splendid subject, by tainting the
purity of the surrounding fluid.

Other specimens have occurred of similar aspect and conformation,
chiefly from four to six inches high, but none above nine. From these
and the former it appears that the higher portion surmounting the main
stem may be confined by an elliptical outline. That is the fashion of its
growth. Thus, one most beautiful and luxuriant, four inches high and
diverging four inches, might have been circumscribed by an ellipse two
inches and a quarter across. By gross computation, 1200 hydrae, deeper

* The proper definition of verticillate might be, a regular form, like the spokes issuing
from the nave of a wheel at first horizontally, and then turning upwards.

TUBULARIA. 53

coloured than peach blossom, decorated this latter specimen. All had fallen
on the third day — none whatever remained.

Such specimens are dark and bushy, the hydras commonly pale,
sometimes almost white. Except in colour, I have been unable to discern
any difference between those ornamenting the larger specimens of this
Tubularia in thousands, and those of fine and florid red and yellow on small
specimens, where there are very few. But it must be kept in view, that,
as a hydra naturally belongs to every extremity, where the hydrse are
numerous there must be many parts ; where they are scanty, the specimen
being vigorous, the parts are few.

Perhaps the dimensions of the Tubularia ramea in a salubrious situa-
tion much depends on age. Those specimens less mature have fewer
boughs, branches, and twigs, but the last always terminated by a hydra.
Though void of that surprising luxuriance above described, many are
extremely beautiful to behold. All the parts and proportions are of ad-
mirable symmetry ; the length of each twig being about double the expan-
sion of the hydra. — Plate X. The stem of such specimens is of dark
umber colour ; the hydra red and yellow. This, the hydra, which is the
organic part of the product, considered externally, consists of a single
row of 24 obtuse muricate teutacula, bordering the disc and around the
stomach, which rises as a central prominence of variable form.* This
pouch or stomach is sometimes flattened almost down to the disc on dis-
charging its contents. The hydra expands about a line between the oppo-
site tips of the tentacula ; therefore, it is smaller than that of either of the
preceding Tubularice, but its dimensions surpass those of any of the Scot-
ish SertularicB with which I am acquainted. — Plate Vlll.figs. 1, 2, enlarged.
The tentacula are endowed with sensible action ; and the head always
expands and turns towards the direction whereby light is introduced ;
but it has no influence whatever over the twig or the stem by which it is
borne. Therefore the naturalist who is told oi flexible zoophytes must
beware of believing in their voluntary motions — that they bend sponta-

* Muricate, resembling an assemblage of low jiyramiJs, with slight intermediate im-
pressions.

54 ZOOPHYTES.

neously. Very few enjoy that faculty ; some only to the slightest extent.
All the Tuhularice and Sertularice are in this sense inflexible, in as far as I
am aware. Many zoophytes, indeed, including these genera in earlier, and
some in the latest stages, though growing upright, are incapable of sus-
taining themselves when deprived of their native element, which is not
rendered sufficiently explicit by those characterising them as flexible.

But there are, in fact, several which are completely so. Single Vor-
ticellce, for example, can bend and turn and twist in all directions ; they
can almost cast a knot on their tender and delicate stems. Microscopic
shrubs composed of similar animals, hundreds of campanulate hydrse ter-
minating their extremities, while at their highest enjoyment of full ex-
pansion in some favourable position, will suddenly collapse on a momentary
alarm, crouching close down to the root in absolute quiescence. Then, as
if relieved from the apprehension of danger, they rise again to display
their beautiful proportions. — Plates XII. XXI.

The younger and smaller Tubularise and Sertulariae consist of a single
hydra, sustained on a fistulous stem, a character unalterable with either
the age or dimensions of the indivisa. In some others it remains, while
flourishing twigs issue from the sides : but this is true only with respect to
the earlier specimens of many ; for in those which are older, such as the
Tubularia (Scrtularia) ramea, and the Sertularia ( Nemertesia) ramosa, the
stem having attained considerable diameter, will be found to consist of
numerous parallel tubuli ; and, in both it is quite inflexible, remaining up-
right, though the smaller parts yield when unsupported by the water.

Different portions of the branches of the Tubularia ramea are indented
by whorls, and especially the extremities. — PI. VIII. fig. 3. But for the
most part they are faint or altogether obliterated : nor do these seem one
of the constant characters.

The head or hydra of this product is deciduous, like the hydrse of the
two preceding species ; also like them, it enjoys the remarkable preroga-
tive of regeneration, — though perhaps for another purpose, because it is
not there that the elements of posterity reside as in the former.

The duration of this most important part of its organization is inde-
finite. Of 80 vigorous hydrse which embellished the specimen, Plate VII.,

^J.

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£1^1^ by C /"^wnjtfK. ^UiuiX

TUBULARIA. 55

when withdrawn from the sea, only 40 subsisted on the second day ; 30
on the third ; 12 on the sixth ; 4 on the seventh ; 2 on the eighth ; on the
tenth there were none : the whole had fallen. This was a beautiful speci-
men. It might have been circumscribed by a circle the size of a shilling.
The dimensions of another, alike beautiful, and more luxuriant, with the
colours finely contrasted, were no larger. — PI. X.

The head survives its fall for a short time. It generally wastes away
suddenly, without falling. Likewise its decomposition is rapid. Though
many have wasted or fallen in the course of a night, none are to be dis-
covered at the bottom of the vessel next morning.

From the transparent cylinder now remaining, the summit appears to
have been penetrated by a prolongation from below the disc : but the
point of union with any internal pith or medullary matter is imperceptible
during the hydra's life : Nor is this same hydra retractile, as already ob-
served, there being no vacuity for its reception.

The nascent bud rises within the hollow tube, to replace the fallen
hydra, precisely in the same manner as that of the Tttbularia indivisa.
Those of largest size after protruding from the extremity, but before burst-
ing their involucrum, are twice the diameter of the stalk. The new tube
sustaining the regenerated hydra, though often much smaller than the
stalk to which it is united, speedily expands as the head advances. Its
delicate and pellucid red is finely contrasted with the dark umber of the
older parts.

Much of the colour, size, and general aspect of specimens, depend on
age ; but as the new hydrise do not exceed the size of their precursors, the
proportion of the organic to the inorganic part is certainly diminishing,
because every addition to the latter is permanent ; and every regeneration
of the former is transient : Neither is the evolution of additional hydrae to
be compared with the multitude of the other parts.

The generation and display of the embryo may be governed by the
same rules which predominate in the preceding species.

A beautiful group of six or seven specimens, chiefly two inches and
a half high, bore numerous hydrae on the 12th of February. All had
fallen in three days. But in other twelve, many new heads were

56 ZOOPHYTES.

flourishing ; and many buds in different stages appeared among them.
The least mature had a slight enlargement at the end of their respective
twigs ; and the most mature a dark ovular or ovoidal formation sustained
on a short neck. — the generating tube. The distribution, proportional in-
crement, and perfection of the renovating parts, rendered the aspect of this
group very interesting. Alike so were the subsequent changes. After
all the heads had fallen, no germination was perceptible on the 22d of
February. But fifty or sixty buds and hydrse appeared in forty hours, and
in another day that number had doubled. Almost all the twigs were
flourishing vigorously on the 2d of March. Above three-fourths of the
heads had fallen on the 8th ; and on the 10th, only one remained, which
went to speedy decay. In the next place, a few buds again protruded
from the extremities, on April 29 : several flourished from the tallest
stem on the 4th of May. Many irregularities ensued, but reproduction
was general on the 13th of June.

The more minute the objects, the greater the difliculty of following
the progress of reproduction, whence fewer illustrations can be obtained.

A branch, not exceeding three lines in length, had borne heads on
three twigs, *', y, z. The head x fell March 3, leaving the tube it had
generated an eighth of an inch long and lighter coloured than the rest.
A bud now rose visibly, within the cylinder, and burst on the 29th ; thus
requiring 26 days for maturity, — the head preceding it had required 23.
Having flourished 8 days, it fell April 2. Another head burst on May 3 ;
thence the reproduction occupied about 29 days. Its subsistence was
now more transient, for it fell in 6 days. A new bud, visible on the 11th
of June, burst with 24 tentacula on the 12th, or in 33 days from the de-
cay of its precursor, and it subsisted during 7. The twig flourished again
in 16 days, and the renovated hydra remained 10. But the neck by this
time becoming foul, no farther regeneration could be followed. So much
for the extremity x. The twig z, being vacant, alike, on March 3, did not
flourish until the 3d of May, that is, for 60 days, when the head then rege-
nerated subsisted 7. But now falling, it had no successor. The twig ?/
generated a head 29th March, which head subsisted 7 days, but it produced
no more.

V.I.

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TUBULARIA. 67

The preceding observations prove : — 1. The same twig bore at
least six successive hydrse. 2. The subsistence of the hydra was from 6
to 10 days. 3. The interval required for reproduction required from
16 days to 60. These irregularities are extraordinary.

The ascent of the bud is gradual ; and it is visible within the tube
for two or three days before its evolution.

Thus certain analogies are found between this product and the two
preceding in the structure of the inorganic parts, and in the regeneration
of successive hydra% from the same portion of the same specimen; nor
are the predominant irregularities in less correspondence.

Propafjation. — Regarding the propagation of the zoophyte, which
must certainly influence its position in the Systema, many years elapsed
before my observations established the peculiar mode whereby it is ef-
fected.

A splendid group of above fifteen specimens occurred on a live mussel
shell. One of these, not 18 lines high, bore 83 hydrse ; and another some-
what taller above 100. At least a thousand animated beings decorated
the group — a wonderful assemblage of variety and beauty on such a scale.
Numerous clusters like yellow ova were interspersed among the hydrae,
not within the circuit of the ten taenia, as with the Tubularine of the pre-
ceding chapter, but generally around the exterior of the under surface or
base of the disc, though disjoined from it ; and sometimes as if compres-
sing the hydrse by their number and position. But they were neither
confined to any particular place, nor peculiar to the finest of the specimens.
Subjected to the microscope, these substances proved of a smooth uniform
surface, exactly resembling a minute ovoidal plum, attached by a short
pedicle to some part of the stem, but never within the hydra. All in one
specimen were ovoidal, those of another irregular, spherical, or ovoidal.
They were single, in pairs, or in clusters of seven or eight together. —
PI. VIII. figs. 5, 6.

The whole were preserved most carefully for a long time, but I was
disappointed of ascertaining their nature, nor was I more successful in re-
spect to some other specimens of the same product.

Eleven years afterwards, however, several specimens having occurred,
VOL. I. ^

58 ZOOPHYTES.

which bore fine florid hydrae, like those of the Tubularia represented
Plate VII., I found minute yellow objects like plums, as before, on different
parts ; two on some, and on others five or six. Many of the hydrae exhi-
bited symptoms of decay, when these were in their immediate vicinity.
All were preserved with equal care as previously.
The yellow plums proved at length to be so many ovaria, analogous
to the clustering cysts already described in detail, though differing some-
what in various particulars ; for they neither corresponded in position or con-
sistence, nor in the connection of a number by a pedicle affixing them to
a common stalk, nor in their contents. In fact, they may be almost iden-
tified with the vesicles or pods borne by the Sertularise, which remain for
ample discussion in their proper place.

Each of these minute yellow plums is a separate and independent
pod or vesicle, wherein, no doubt, an ovum is originally generated, but
discharging an animal intimately resembling a Planaria, and which, for the
purpose of ready and familiar recognition, I shall venture to designate
flmudii. The conventional name of larva, which there is at present so
strong a disposition to incorporate in the vocabulary of natural history,
seems scarcely enough expressive of its character.

Only a single large bright yellow planula is contained in the vesicle,
whence it is discharged on maturity from an orifice towards one side near
the summit. But the vesicle itself is of such extreme transparence, that
it is hardly visible, after losing its contents.

This animal, the planula, is taper, roundish, or somewhat flattened,
not half a line in length, of smooth, uniform, fleshy aspect, void of exter-
nal organs. It crawls with considerable activity below ; and on ascending
by the side of its vessel to the surface of the water, it either descends
again, or pursues a course at the edge ; or committing itself to the element
it swims supine. It changes its situation freely, testifying evident pre-
ferences, and it is of infinitely greater activity than the nascent hydra after
being discharged, and during its evolution from the cyst of the Tubulario
indwisa.—V\. VIII. fig. 7.

Certain learned naturalists, whose opinion I highly respect, have ex-
pressed their doubts of the animation of this being, without having seen

PLoIX.

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TUBULARIA. 59

it, on my endeavouring to describe its properties. But it seems to me
conclusive, that if a moving bodj, meeting an obstacle in its course, passes
around instead of remaining still, or if it retraces a given track, and changes
its direction according to circumstances, sufficient evidence is afforded both
of animation and of volition.

The planula is soft and of variable form ; and it continues crawling
about for an indefinite time. Then its motion relaxes, it shortens and
thickens, and appears as if composed of two portions, a larger and smaller,
both very obtuse, and next it is found affixed to some solid substance. —
Fig. 8.

In four days after this active creature has been discharged as a minute
Planaria from the vesicle of the beautiful shrub, studded with numberless
animated flowers, it becomes altogether metamorphosed — for now a living
hydra is borne on a fistulous stem with a diffusing root below. — Fig. 9.

In the middle of November, an aged specimen, clinging to the tube
of an Amphitrite, bore white hydra;. All the branches were invested by
hundreds of clusters, composed of a number of prolific pure white vesicles
crowded together and resembling minute eggs.

Another fine specimen of the product obtained towards the end of
September, five inches high, and apparently very old, was remarkable for
the profusion of pure white vesicles on the branches, which were disposed
in clusters of five, six, or seven together. — Plate IX. fig. 1. — The same
enlarged, fig. 2.

The hydrse of this specimen were not numerous ; they were small,
nearly white, some of the faintest carnation.

Within a few days, many planula?, all pure white, had been discharged
by the vesicles. They were of corresponding figure with the former;
an obtuse rounded head,* thick and fleshy body, tapering towards the tail
or lower extremity, which was also obtuse. — Plate IX fig. 3.

The number of planulse continued augmenting ; but, in a short time,
their motion relaxed. They became stationary and quiescent, and the
alteration of their shape announced approaching metamorphosis. — Fig. 4.

* By this word rounded is to be understood, not simply obtuse, but something tending
to a circular arc.

60 ZOOPHYTES.

Here, as before, they seemed forming into two portions. Meantime a root
was diffusing below, and a stomach forming above, fig. 5 ; and the higher
portion by the gradual refining and improvement of the parts was deve-
loped as a perfect Tubularia. — Fig. 6.

The progress of this zoophyte is rapid ; sometimes the nascent hydra
flourishes in six days after the discharge of the planula from the vesicle.
It is now furnished with from 12 to 18 very muricate tentacula, for the
number is variable in individuals. Indeed, there is almost a common and
singular irregularity of the subordinate parts, not only in the nascent, but
in the mature hydra of many zoophytes. From such extraordinary irre-
gularity or variety of aspect, it is less surprising that considerable diffe-
rences are seen in the figures presented by authors, besides which there
may be some difference in the aspect of the same species of animals found
in various countries. Yet it is not to be denied that many imperfections
orio-inate, first, from neglect in selecting the finest specimens, secondly,
from inability to obtain the service of competent artists. Let it be re-
membered that an alteration of the position of a subject will often bring
a whole series of organs into view which were previously unnoticed.

The formation of the root of the Ttthularia raii/en is definite and con-
spicuous— generally forking from the centre into four radicles, full of pith
like the stem, which extend far, and occasionally exhibit a subdivided ex-
tremity. Four radicles seem the regular complement. Herein is a great
distinction from the Tubularia proper, and a strong analogy with the Ser-
tularia. I mean in the formation of the root.

I am not aware that there is any essential difference between the
nascent animal from the yellow vesicle and that from the white vesicle.
The root of the former seemed diffusing amidst a transparent matter, which
from colour might be inconspicuous in the latter. We shall afterwards
find some correspondence in these points with the Sertularia.

Both nascent products from the yellow and the white planula rege-
nerate the hydra. That of a nascent specimen from a yellow vesicle sub-
sisted 23 days ; in 10 days from its fall, it was replaced by one which
subsisted 4 or 5.

The position and aspect of the vesicles are represented Plate VIII.

TUBULARIA. 61

figs. 5, 6, 11, 12, 13, 14, and Plate IX. fig. 1, 2. The planulse from the
vesicles are seen Plate VIII. fig. 7, and Plate IX. figs. 3, 12 ; the com-
mencement of their metamorphosis Plate VIII. fig. 8, Plate IX. fig. 1 3,
and the progress of the nascent Tubularia from an early stage to perfec-
tion, Plate IX. figs. 5, 6 7, 8, 9, 14, 15, 16, 17, 18, 19, and Plate VIII.
fig. 9.

A monstrous hydra crowned the stem of a specimen bred from a pla-
nula, Plate IX. fig. 10 ; and two stems, a, b, issued from the same root of
another, fig. 11 — three roots from fig. 14 — five from fig. 15.

Clusters of corpuscula of uncertain nature are seen, though rarely, at
the summit of such stalks as have borne hydrse. They bear some resem-
blance to a compound vesicle, consisting of a spherule, sustained on a pedi-
ment. From 10 to 20 compose the cluster. — Plate VIII. fig. 10.

The various aspects under which almost all zoophytes occur occasion
great embarrassment to the observer. There is scarcely any naturalist who
fails to assign a series of whirls, or whorls, to different parts of the stalk of
these Tubularise, as I conclude. Yet there are many of those now de-
scribed wherein no such feature can be recognized. The stalk or twig
remains smooth and even — quite plain from its origin up to the head.
Others exhibit 8, 12, or 16 whirls, like prominent annulations ; but they
are frequently very faint and indistinct : nor have I ever seen the deep in-
dentations, like a coil of ropes, represented by authors. A specimen, very
old, though not taller than two inches, bearing hydrse, had none. Probably
whirls of the neck are exposed through a transparent membrane in their
early growth, while they may be subsequently disguised or at last oblite-
rated by supervening age and opacity. Naturalists are very prone to re-
present microscopical objects or those, simply viewed by a lens, with
features infinitely stronger and more definite than the truth. But many
allowances must be made for the difficulty of obtaining the finest specimens,
or a suitable view of them, and, above, all a competent artist. No one
but he who would practically study the science for a protracted series of
time, and wishes the world to profit by his labours, can appreciate the em-
barrassments opposing his representation of the identical subjectand its parts.
The Tubularia ramea grows either as a very bushy shrub, upright,

62 ZOOPHYTES.

and free, with a grey or a brown stem, and Lydrse of vivid red and yellow,
faint carmine, or almost white : Or it runs as a thread in adhesion to sub-
jacent substances, merely shooting up twigs, and sometimes branches at
intervals. Then the twig is crowned by one, and the branch may be ter-
minated by ten florid hydrse. Adhesion of the stem, whenever contact
with a foreign substance ensues, is a peculiarity incident to most Sertu-
larise ; and then it appears that the vegetation, which should naturally
issue from the sides, if free, originates from the upper side only, the others
adhering to the substance.

The difference between a luxuriant and a stunted specimen is in-
credible.

None of the zoophytes can be compared in luxuriance and beauty to
the Tubularia ramea ; or can excite greater interest in beholding such an
animal product with its thousands of living parts growing from the same
spot, aflixed like a vegetable to the earth.

Its nature is prolific, for the vesicles of some amount to thousands.
Yet it is not more — if equally prolific with others ; as the vesicle con-
tains only a single embryo, whereas the vesicles of some Sertularia; con-
tain above twenty. I cannot say whether any positive determination of
genus or species is to be founded on the paucity or the profusion. The
question merits investigation,

I have not seen any specimen higher than nine inches, or more than
ten in divergence. Such are large zoophytes. The stem is then com-
posed of numerous tubuli. I do not well comprehend how the accessions
are gained to the single tube peculiar to early age. In their multiplied
condition, the tubuli appear as free and independent or united in clusters,
which may be seen from the section, PI. VIII. fig. 15. Similar speci-
mens are always imprinted with the marks of venerable antiquity.

Plate VI. Tubularia (Sertularia) ramea ; aged specimen.

VII. Tubularia (Sertularia) ramea ; adult enlarged.

Plate VIII. Fig. 1. Hydra of Plate VII., enlarged.
2. Hydra of Plate VII., enlarged.

PX X.

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TUBULARIA. 63

Fig. 3. Stem, branches, aud hydrse of another specimen, shewing
the arrangement of the parts, enlarged.

4. Branch of a specimen, illustrating the regeneration of its

hydrse from x, y, z.

5. Vesicles compressing the hydra, enlarged.

6. Vesicles, partly dispersed on a branch, partly compressing

the hydra whereby the variety of their form is illustrated,
enlarged.

7. Planulse from yellow vesicles.

8. Planula metamorphosing.

9. Nascent hydra, previously a planula.

10. Vascular substances of uncertain character.

11. Branch bearing hydra and vesicles.

12. Branch bearing hydra and vesicles.

13. Part of a specimen with hydrse and vesicles, enlarged.

1 4. Vesicles variously distributed, and hydra.

15. Transverse section of the stem of the aged specimen,

Plate VI.
All the figures of this Plate, except fig. 4 and fig. 13, are
enlarged.

Plate IX. Tubularia (Sertidaria) ramea. Propagation.
Fig. 1. Branch with white vesicles.

2. The same, enlarged.

3. Planulse from white vesicles.

4. PlanulEC in different stages of metamorphosis.

5. Nascent tubularia ; root forming below ; and stomach above.

6. Nascent specimen.

7. Nascent specimen.

8. Nascent specimen.

9. Nascent specimen. — The cruciform root is not distinctly ex-

exposed, in figs. 6, 7, 8, 9, from interception of the view.

10. Nascent specimen, apparently monstrous, from the position

or form of the hydra.

11. Nascent specimen, considerably advanced.

12-19. White planulse and their metamorphosis, in November.
All the figures, except the first, of this Plate, enlarged.

Plate X. Tubularia (Sertularia) ramea, enlarged.— The original might
have been circumscribed by a circle an inch in diameter.

64 ZOOPHYTES.

§ 2. TuBULARiA (Sertularia) Ramosa. — Plate XI.

The preceding observations apply to those animal products resem-
bling plants, whereof the hydra, head, or flourish, crowning the extremity
of the tubular extremity of the stem sustaining it, remains permanently in
its place during life, because there is no lower cavity adapted for its re-
ception. The cylinder, though hollow, is occupied by a peculiar sub-
stance. It is otherwise with the subject of the present paragraph ; whence
observers, on becoming better acquainted with its nature, may remove it
from this intermediate position, to be incorporated with the Sertularise,
which, from the structure only, are apparently of nearer kindred. Mean-
time certain peculiarities of extreme interest, concomitant on the few
specimens falling into my possession, will perhaps atone for any deficien-
cies of description, classification, or nomenclature, more especially as these
can be readily corrected by those learned authors devoting themselves to
systematic arrangement. The multiplication of facts may facilitate their
useful labours.

While occupied, early in June, with the Fennaiula mirabilis, or Virgu-
laria, as it is now denominated, I found the lower extremity of three different
specimens invested by the zoophyte, under discussion. Many others also
subjected to observation at the same time, were quite free of it. This
lower extremity is usually a naked bone, protruding beyond the flesh of
the Virgularia, or it is covered with a dark skin, being perhaps the fleshy
part of the lobes, which shall be afterwards described, in a contracted
state.

A colony of 20 or 30 of what I judged to be the Tuhularia ramosa
invested the lower part of the largest of the Virgularise, radiating as it
were from around it. — Plate XI. fig. 1. It will be seen that they issue
from the circumference of the bone.

Here the stem of the Tubularia, about an inch high, was surrounded
by branches in somewhat of an alternate arrangement, shortening as they
rose upwards ; a few were subdivided into twigs : all the extremities were
tubular, without any enlargement, and each was terminated by a hydra.
The formation is in no respect dichotomous, that is, each larger portion
subdividing into two lesser ones, and these undergoing a similar partition.

TUBULAEIA. 65

Faint whirls, almost inconspicuous in the living product, indent the origin
of the branch and the ea-tremitij of the twigs. Chestnut brown or umber
is the predominant colour of the inorganic parts ; the hydra, very minute,
is reddish. — Plate XI. fig. 2, enlarged.

As the extremities of this product consist of hollow cylinders, with-
out any cellular enlargement, the hydra retreats simply within for protec-
tion. "When rising, it is protruded by a very long flexible body or neck,
capable of great recurvature, which is bordered by from 6 to 14 muricate
tentacula, environing an obtuse central cone — the stomach. The tenta-
cula are susceptible of much elongation, when they become almost of
cylindrical form. The stomach is indicated by a rough dark line de-
scending far within the body. — Fig. 3.

Although the hydra protruded from the extremity of a cylinder, some
issued immediately from the side of the stalks, without the obvious inter-
vention of a tubular twig.

The great flexibility of the neck induced me to consider this product
as allied to the Coryna, on obtaining a smaller specimen many years ante-
cedent to those now described ; nor even now do I speak positively of the
name and species. It is susceptible of complete recurvature, or of look-
ing behind, as we should express of other animals.

Naturalists have affirmed that a circulating fluid subsists in the Ttibii-
laria indivisa, a zoophyte of considerable magnitude, and of which the or-
ganic portion exceeds the dimensions of the corresponding part of any
of the other corallines. IVIy inability to discover it, though resorting to
numerous specimens of every size and age, has been already explained.
But I have witnessed it very satisfactorily in the present subject, under
peculiar circumstances, not by one, but by repeated observations.

When the hydra is brought into a horizontal position, dark particles
are seen ascending one side of the neck and descending by the other, as
if conveyed by the current of a fluid. But the sides of the channels con-
taining them are invisible, perhaps, from tenuity ; nor is it undoubted that
the currents absolutely flow on the opposite sides of the animal, for the
channels may be separated by a smaller interval. Relative position in ob-
jects so minute is extremely delusive. The current is chiefly visible at the

VOL. I. I

66 ZOOPHYTES.

lower part of the head. A prominence on the neck of a hydra, Plate XI.
fig. 4, exhibited similar currents, though less distinct.

The rate of such currents is not altogether uniform. This, indeed, is
seen in the Ascidia, and various kinds of the lower animals ; and in many,
their acceleration or retardation must result from the mutable form of the
subject. Sometimes the particles are carried along with considerable velo-
city in the hydra now described.

This hydra has no power over the skeleton, which, in comparison
with it, must be considered rigid.

The same vegetative faculty distinguishes the present species as many
Sertularise, for, having cut two portions from a specimen, I found them
rooted to the glass whereon they lay in the course of a night.

Medusa ocilia. — Practical naturalists must be well aware that nume-
rous colonies of minute Medusae, and even successive generations of them,
sometimes appear in vessels containing various marine collections. But
it is extremely diflScult to pursue the history and progress of such trans-
parent, unmanageable, and too often evanescent beings. Their sudden
existence has surprised me again and again. I was unable to ascertain
their origin ; they have remained some days in activity, then vanishing
without leaving the slightest traces behind. No species could be pre-
served with facility, though for only a short period ; they did not seem
referable to any particular time or subject. Every thing regarding them
was wrapped in mystery.

The smaller the objects, indeed, and the less conspicuous their aspect,
independent of the delicacy of their perishable nature, the more restricted
the scope for permanent observation. Yet there are some so hardy, and
so readily beheld, not a tenth part of the dimensions of their fellow-tenants
of the waters, which may remain so long as to disclose their own his-
tory.

While a number of vigorous hydrse still terminated the extremities
of the zoophyte above described as the Tubidaria ramosa, I suspended
various specimens by silk threads, in vessels of sea-water. This is a method
to be particularly recommended for convenience and security ; the subject

TUBULARIA. 67

is better preserved, the parts more accessible, and by immediate trans-
ference, it can be always kept in the purest medium.

Several white specks among the twigs issuing from the branches then
became perceptible by the naked eye, which, under the microscope, proved
to be small solid pear-like substances of bluish-grey colour. Thence I
proposed to denominate them pyrula.

Thinking little more of the matter at the moment, I concluded they
might be regenerating hydra, as not unusual with different zoophytes.
But my attention was soon arrested by the position of some as if seated
on the long neck of the living hydra. I could not doubt that one neck
sustained three, and that elsewhere a cluster of four appeared at the extre-
mity of a twig then vacant of a hydra. Further investigation ascertained
the following facts.

Minute pyriform bodies, as above specified, are dispersed on the stalk
of different parts of the Tubularia, at considerable intervals ; sometimes
three are together, sometimes two opposite to each other ; or only one
terminates a twig, where it might be readily supposed a regenerating
hydra. — Plate XI. figs. 5, 6, 7. Each pijrulum is affixed by its own dis-
tinct pedicle, at first of some length, but gradually shortening as the
remainder becomes more globular, or flattens. In a few days, the whole
may be compared to the opening bud of a white rose. — Fig. 8.

Now the dilatation and collapse of the subject commence ; convulsive
struggles ensue ; four pair of long rough muricate organs resembling ten-
tacula, or ciliary processes, are gradually unfolded ; and after what seems
repeated severe and protracted exertions, a perfect animal of great trans-
parence is liberated as a Medusa, suspended amidst the waters. —
Figs. 9, 10.

This Medusa resembles a large transverse section of an ovoid, not
half a line in diameter, the sides of excessive tenuity, the tentacula, or
ciliary organs, four or five times as long as the diameter of the ovoid, and
quite flexible. I conjectured there might be an orifice in the upper sur-
face, and that some stump or particular organization by which it was pene-
trated, and remaining behind, the animal amidst its struggles was kept in
its place. It is the upper surface which is that in application or adhesion,

68 ZOOPHYTES.

as may be seen of others, the lower portion whence the cilia originate is
meantime free. Here, as we know, the mouth or proboscis of the Medu-
sarian race is situated. In the under surface four cruciform organs were
apparent. But the difficulty of ascertaining relative position is never to
be forgot ; and, in fact, organs apparently below in such creatures may be
in the middle, or actually above.

As in some other Medusae, the ciliary, or tentacular organs, resemble
knotted cords. Each pair originates from a prominent knob or button on
the margin of the cavity in the under part ; and a black speck, like an eye,
is conspicuous at the root of each tentaculum : there are, therefore, eight
in all. The transparent convex surface of the animal is crossed by two
darker lines at right angles, as if dividing it into quarters, and terminat-
ing in the four buttons or knobs on the margin.

The opacity of this creature during its earlier stages is not such as
entirely to intercept the light, though its transparence refines in proportion
to the evolution of its organization. Thus, the cross lines running from
what was conjectured an orifice is discovered to be four vessels, wherein a
fluid carries a number of black particles down to the marginal knobs below.
It rather appears also, though I could not satisfy myself of the fact, that
the current may pass in another course around the margin.

We should be much deluded, as well as our fellows, in believing that
sufficient opportunities are afforded for similar observations by the Me-
dusa, free of the zoophyte, and swimming at large. On the contrary, they
can be effected only while immaturity yet restrains the animal to its pris-
tine site ; and where, during progressive evolution, the microscopical focus
can be accurately adjusted for distinct vision. The motion of so restless
a being, when liberated, renders correct observation incompatible with
that condition.

One of the pyrula seemed to be united to a hydra, just at the orifice
of the twig from which it issued. Circulation manifestly advanced in both.
Black particles were carried up as well as down the neck of the former
the pyridum ; and during their descent, a current was obviously convey-
ing black particles up the body of the hydra ; something similar seemed
to be going on in an isolated pyrulum, where there was no hydra.

TUBULARIA. 69

All this appeared to me very singular ; because it is unusual, at any
time, to obtain such facilities from transparence or otherwise, as to allow
disclosure of the hidden and mysterious operations of animal life. Per-
haps I might have comprehended the process advancing better had the
zoophyte borne an ascidioidal hydra, because the sanguiferous system is
visible in various species at their various stages. But I had no reason to
remove the hydra of the Tubular ia ramosa, from its alliance with the
structure of the polypus proper, in as far as that belongs to zoophytes of
the Tubularian or Sertularian tribe.

Among the larger and more perfect animals, it is usually understood
that circulation by the sanguiferous system must advance in a regular and
uninterrupted course, else pernicious consequences follow. But, in as far
as I have seen, no such regularity is indispensable to the health or safety
of some of the lower animals ; nor can we even pronounce it permanent,
where transparence of the subject allows protracted observation. In that
before us, the circulation is sometimes accelerated, sometimes retarded —
nay, it is occasionally altogether suspended — ^yet without evident injury.
Further, there is much ground for assuming that the rate and proportion
of the current are in a certain measure dependent on the will of the ani-
mal, or on the exercise of its faculties over its own organic structure.
Amidst all this, we say the variable form of the soft bodied animals must
be specially kept in view, the extraordinary change and vast disproportion
produced of their different parts, and how much the whole system will be
affected by it.

The provision of Nature for conducting a vivifying principle through-
out the whole extent of animal organization, whereby it shall impart
vigour to the remotest parts, surpasses all the admiration which mortals
can bestow upon it ; and this marvellous expedient is rendered still more
wonderful, by reflecting on the means adopted for its impregnation with
atmospheric qualities devised for the common sustentation of the universe.
Everything conspires to shew the grandeur of the plan from whence the
world has originated. Perhaps we shall at last find the apparent vast diffu-
sion in variety concentrated in some simple elements.

The history of no tribe of living creatures has remained so long in

70 ZOOPHYTES.

obscurity as that in general of the transparent beings which we denomi-
nate MedusEe. It will scarcely prove more intelligible if we shall consider
them only an intermediate race of animals, like the larva, chrysalis or
nymph, among insects, only in the course of transition to some other form
or condition, unless we shall actually witness their origin and their end.

I am not ignorant of the strong disposition of modern naturalists to
establish the nearest kindred between the Hydra, comparatively few in
number, and the legions of the Medusarian family, thickening the very
ocean in their profusion ; but I also know how very prone we are to grasp
at every novelty, and our precipitation in adopting as facts what can be
offered only as conjecture.

I say not this to impugn the observations of those ingenious natu-
ralists who have proved the truth ; but to restrain the hasty opinions of
those who would reason less from facts than from analogies ; and to enforce
the expediency of accurate and continued investigation.

The preceding animals originated and disappeared without leaving
any traces behind. Indeed, the smaller medusae never leave any that I

have seen.

Another species has sometimes appeared and decayed mysteriously,
without affording obvious indications of its origin. — PI. XI. figs. 11, 12.
This animal occurs in April ; the former is developed from June until
August. It is an eighth of an inch in diameter, with 16 long slender ten-
tacular or ciliary organs, disposed in four bundles, which issue from four
marginal prominences. At the base of each set is a black speck. The
transparence of the medusa is such that while suspended in equilibrium
among the water, it is scarcely perceptible.

I shall be probably enabled to say a few words on the Medusarian
race at a future opportunity.

The evolution of the Medusa ocilia is progressive, accelerated per-
haps by external temperature. It has occurred to me under no other con-
ditions than as above specified. A number of whitish corpuscula seem to
be generated, rather suddenly, among the hydrse, either singly, in pairs, or
in clusters of three, four, or five, as already stated. Each is aflBxed by its
independent pedicle, and generally about the orifice of a twig of the zoo-

TUBULARIA. 71

phyte. One wherein no subordinate organic parts were visible, on first
inspection, was observed to unfold in three hours.

There is reason to believe that this Medusa is confined in a diapha-
nous vesicle or involucrum, remaining in its place after the animal has
escaped. If actually so, which requires confirmation, we cannot but re-
cognize strict analogy to the vesicles of the Sertularise, some being hardly
perceptible after discharging their contents, from extreme transparency.

A colony computed at 130 individuals of the Medusa ocilia, was pro-
duced in four or five days : and there are grounds for assuming that suc-
cessive colonies come from the same specimens of the zoophyte.

I cannot presume to afiirm that any connection, immediate or remote,
connects the Medusa ocilia and the Tubularia ramosa ; far less to conclude
that the former shall be metamorphosed in progress of time to the latter,
with its numerous and beautiful appurtenances. I have not seen both
the beginning and the end ; nor does the fugitive existence of so delicate
a creature seem well adapted for permanent observation.

This is not the only example, it is true, which I have witnessed of
Medusarian forms originating from hydraform products, as shall be ex-
plained in the proper place. But we cannot be too distrustful of infer-
ences on such obscure and peculiar phenomena of nature. So many im-
portant facts may elude observation, so many delusive appearances are
ready to bewilder the senses, we cannot desire too ample corroboration.

Perhaps the preceding facts, as well as the subsequent, may stimulate
more intelligent naturalists, enjoying better opportunities than I have had,
to seek their confirmation.

Plate XI. Fig. 1. Tubularia (Sertularia) ramosa, investing part of the Virgu-
laria (Fennatula mirahilis,) or Sea Pen.

2. Branch.

3. Hydra protruding from the extremity of a twig, a.

4. Hydra with an indefinite excresence on the neck.

5. Hydra with three pyrula a (embryonic medusae) at the orifice

of the twig.

6. Pyrula at the extremity of a branch.

72 ZOOPHYTES.

Fig. 7. Pyrulum, a, at the extremity of a branch.

8. Pyrulum, a, unfolding as a Medusa.

9. Medusa ocilia (octocilia), in progressive developement.

10. The same free.

11. Medusa duodecilia (ciliis duodecim).

12. The same, viewed in plane from below.

All the subjects of this Plate, except fig. 1 , enlarged

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HYDRA. 73

CHAPTER III.

THE HYDRA OR POLYPUS.

The preceding facts, sufficiently interesting in themselves, require
some farther illustration, for explaining the general nature of the hydra
or polypus, so often referred to as forming a most essential part of the
subjects described. This will enable the reader to comprehend still more
satisfactorily the peculiar quality of those to follow, especially if never
having himself beheld them in their native element.

From the material difference of organization in those living beings,
which, along with inorganic matter, compose the substance of such ani-
mal products passing by the general appellative of Zoophytes, the name
hydra is employed rather as a conventional term than as a definition, to
signify that active portion endowed with evident sensation and spontaneous
motions. Custom has sanctioned its application, like the use of other
phraseology : it is attended with certain facilities ; and it may tend to re-
press that inordinate multiplication of trivial nomenclature whose subdivi-
sions threaten confusion to both the learned and the illiterate in the maze
of interminable ramifications.

Had this work been more than a mere collection of memoirs from
practical observations — a siinple detail of facts — the useful arrangements of
Dr George Johnston might have been beneficially followed as a guide ; for
that learned author, commencing with the hydra, lays down the elements
of an easy partition of zoophytes, founded on the nature of the animated
portion. He distinguishes them as Hydraoidal, Ascidioidal, Helianthoidal,
and Carnose.

In as far as I am aware the hydra proper — that is, the polypus of

VOL. I. K

74 ZOOPHYTES.

older authors — is a simple animal, uncombined with any other organic
structure, and which, on dissection, has shown but little to the anatomist ;
and that its form is permanent from the origin to the close of its exist-
ence.

On the other hand, in some instances, the hydra of zoophytes in
maturity is simple ; it is almost always, if not uniformly so in the nascent
state of others. In adult zoophytes, the majority of hydrse are combined
with a simple inorganic structure, often that which is complex, a cell or a
stem, or a boundless multitude of branches and terminal cells, with their
tenants all enjoying an independent condition or reciprocally connected
together. In some this connection is obvious; in some obscure; and
masses of thousands of pinnate hydrse comprise the living animals, scarcely
separated by a fleshy partition in the carnose tribes.

There are three hydrse in Scotland which I consider strictly of the
individual nature of the hydra proper — namely the Hydra viridis and the
Hydra fusca of the Systema — both inhabitants of the fresh waters; — and
the Hydra gelatinosa, strobila, or tuba, of the sea, which appear synony-
jyious : — as hydrce all exhibit common properties. The body consists of a
variable sac, having a dilateable orifice environed by tentacula, endowed with
an adhesive and a prehensile faculty. The whole are highly carnivorous ;
they propagate the young in their own likeness, by gemmation or budding
from the side ; they regenerate mutilated parts : and adults, as well as
young, if cut asunder, become entire animals.

Being hardy by nature, easily fed, preserved, and subjected to experi-
ment, they are peculiarly adapted for minute and protracted study. Their
accessibility, their size, and tenacity of life besides, wherein they surpass
most of the zoophytical tribes, render them favourable objects for observa-
tion ; because the delicacy and minuteness of many others, not omitting the
higher organization of a number, truly removing them from the genus
Hydra, deny the same facilities to the naturalist.

When the fresh-water polypus became better known, before the
middle of the preceding century, its singular properties aroused the admira-
tion of those who devoted themselves to the investigations of Nature. To
behold a living animal perpetuate its race, by simple gemmation from the

HYDRA. 75

side, like the bud of a vegetable ; and while the offspring was yet adher-
ing to the parent, to witness another — a second race of descendants —
originating from the first generation, seemed a disturbance of the ap-
pointed order regulating the conditions of existence. But, above all, to
find a being endowed with life and sensation, as if indestructible under the
edge of the knife, so that privation of the most important parts of the
frame for conducting the vital functions, was only a prelude for the de-
velopement of others to supply their place, revived the fabulous hydra of
the ancients in actual verification.

Thus was the notice of physiologists irresistibly attracted to those
energetic qualities of living matter restoring organic integrity.

Extending the field of inquiry, they proposed to apply to other
creatures of the lower tribes, the name of the animal, the hydra, by which
such admirable peculiarities had been displayed. Herein their plan was
partly correct, and partly erroneous ; for, taking only a superficial view of
the aspect of such animals, those anatomical distinctions sanctioning their
transference to other genera, either remained undiscovered, or they had
not sufficient weight to lead to their removal.

Hence it is, perhaps, that hydra is rather a conventional term of
general application than a rigid definition employed to signify that peculiar
structure of the animal exclusively falling under it.

The only Scotish Hydrae of the fresh waters, which I can positively
identify as different, are thefmca and viridis of the Linnean Systema ; the
former with six or seven tentacula, the latter with six, eight, or more.
But the number of each is indefinite. — PI. XII. figs. 14-20, inclusive,
enlarged,

I do not recollect to have found the first with above seven tentacula.
The young are pullulating from the sides of all but figs. 14-17. Fig. 15 was
white or pale grey, which may be an accidental variety.

Neither of these species, especially the green, is uncommon in Scot-
land ; but the properties and peculiarities of the genus having been long
ago so copiously exposed by Trembley, Bonnet, Roesel, Baker, and other
skilful experimentalists, it would be superfluous to discuss their history
here.

76 ZOOPHYTES.

Both of them have been hitherto considered animals in a perfect
state : nor have I at any time discovered in our fresh waters any living
being indicating an origin from their metamorphosis : neither has pro-
tracted observation on themselves afforded room for conjecturing it.

The most learned have not disdained a philosophical view of animals
undergoing successive metamorphoses in their advances to perfection.
Witness the admirable work of Lyonet on the Caterpillar of the Willow.
Therefore I do not hesitate to assume the subject of the following para-
graph, as well adapted for illustrating the general nature of many zoo-
phytes, and in particular, the mode of their increment — independent of its
own singular history. It not only elucidates the character of both simple
and compound genera, but it shows how a thousand individuals may ad-
vance from one by progressive multiplication.

§ 1. Hydra Tuba, The Trumpet Polypus.* — Plates XIII. XIV.

Let me here premise, that some years ago, long after the subject of
this paragraph had come under my notice, I submitted a few general ob-
servations regarding it, to the British Association for the Promotion of
Science, during the sittings of that learned body at Edinburgh in 1834.
As the study of Natural History was advancing but languidly in Scotland,
my principal aim was then, as on previous and subsequent occasions, to
engage the attention of my countrymen with the interesting phenomena,
which they might readily discover among our national products. There-
fore, selecting only the facts most easily attained, nor exacting painful and
protracted study, I sedulously abstained from discussing various other im-

* Probably this is the Hydra gelatinosa of Miiller, Zoologia Danica, torn. iii. p. 25.
PI. XCV. Hauniw, 1789, in fol.

In a work by a learned Norwegian author, Sars, of which I have very recently seen a
copious extract in M. Lesson's Acalephes, he describes what seems the same animal, under
the name of Strobila, I presume meaning the cone.

From his valuable details, it appears that he was the first who revealed to naturalists
the remarkable metamorphosis undergone by the hydra.

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HYDRA. 77

port ant and still more interesting points, though sufficiently acquainted
with them. I believe now that it would have been better had I done diffe-
rently, for it would have prevented certain authors from betraying them-
selves into very erroneous conclusions of the import of my observations.

I shall resume the subject more at large in this place, viewing the
hydra, in the first instance, as a perfect animal.

The body of the Hydra tuba is a hollow cone five lines in length,
thick and fleshy. Thirty or more very extensile, flexible, fine slender
muricate tentacula descend twenty-one lines from the margin, collectively
forming a beautiful silken-like pencil waving amidst the water. The
mouth rises as a conic frustum among them, in the centre of the disc,
much resembling the closed mouth of the Actinia ; but there is no analogy
to a proboscidal organ, either here or in any other of the hydraoid race.
The natural colour of the animal is universally dingy white, sometimes
faint orange, perhaps according to the season, but it is specially affected
by the quality of the food. It is affixed by the apex ; and is exclusively
an inhabitant of the sea. — PI. XIII. fig. 1.

Throughout there is a strong analogy in many prominent features of
this animal to the nature of the Actinia.

Complete developement of all the parts of the Hydra tuba is best
exposed under temporary abstinence : the observer will be disappointed
of seeing them if resorting to his specimen in a state of repletion. While in
abstinence, the animal remains suspended by the apex, the body lengthens,
and the tentacula are extended to the utmost stretch in quest of prey.
If sensible of its presence when inaccessible, the hydra does not em-
ploy them as instruments of capture in sweeping around, but the mouth
widely dilating, projects the edge as a thin flexible lip in much action.
Now, the capacious cavity of the stomach indistinctly exposes a kind of
columnar range around the internal parietes, possibly corresponding with
the external form of the body, at times bearing faint resemblance to a
cluster column. Exposure so complete is very rare. The stomach is most
capacious : when coloured food gorges the hydra, it is seen nearly at the
apex ; indeed, excessive distension seems to detach the animal from its
point of adhesion, when it falls to the bottom of its vessel.

78 ZOOPHYTES.

This is a creature far from being nice in the selection of food. It
preys readily and greedily on most animal substances, and the quantities ab-
sorbed, are altogether disproportioned to its dimensions. Among the victims
of voracity it is singular that living young Actiniae should be acceptable
prey, considering their congenerous nature, and the more so, that they seem
incapable of making any exertion for self-preservation. In return, the
hydra is devoured by the Actinia, — all conform to the general law whereby
the weaker among carnivorous animals falls a prey to the stronger.

When sated, the hydra remains motionless, with the tentacula closely
contracted. Judging by the long continued exposure of coloured food
through the skin, digestion is probably very slow. If originally copious,
the food is rejected by the mouth in a half-digested state, as with the Ac-
tinia. Like it also, if sparingly supplied, the whole is apparently absorbed
into the system. Sometimes the mass is retained several days, though
usually rejected sooner. The residue of a very voracious meal has been
retained ten or twelve.

In farther correspondence with the Actinia, the senses of this hydra,
excepting touch, are certainly most obtuse. Hunger merely induces the
extension of the tentacula, but there is no evidence that the presence of
the prey is discovered, otherwise than by actual contact. No searching
activity of the tentacula is shewn even when food is within their reach : no
perceptions regarding it are betrayed, unless the action of the lip, as above
described, can be an indication ; and although the roots of the tentacula
become somewhat more apart, and consequently greater dispersion of their
extremities, nothing proves that it is for any important purpose. How-
ever, the animal is capable of raising large portions to its mouth ; and its
pendent position is clearly the natural one, and for aifording greater scope
for the exercise of these flexible organs.

Speedy increment follows copious sustenance. All hydrse are then
rapidly enlarged, attaining tenfold their previous size, if regularly fed ; and
they become proportionally prolific. Along with emaciation, the colour
fades from- protracted abstinence.

This is an animal very impatient of the effects of light. While the
whole organs are finely displayed in comparative obscurity, they con-

HYDRA. 79

tract quickly, on removal to the light, and always as if to evade some
painful impression.

Probably adhesion is spontaneous, as with the polypus of the fresh-
waters and the Actinia of the seas. But the Hydra tuba commonly re-
mains stationary where it has taken a position ; if affixing first to the bot-
tom of a vessel, it continues permanently there. If dropping from its
place when affixed to the side, or should the water be repeatedly agi-
tated while either adults or young are loose, they seldom adhere after-
wards ; nor does the animal fix readily at any time.

Its trumpet form is sometimes entirely lost, and the figure of a hand
bell assumed by the upper portion of the body, near the fixture of the
apex, relaxing like a coarse thread, extending two lines or more. Then
the remainder of its pendent body flattens in a campanulate form. When
several of a group assume this figure, inexperienced observers might be
deluded by the change.— Plate XIV. fig. 26; XX. fig. 19, a.

A locomotive faculty, though rarely exercised, and only in the lowest
degree, is undoubtedly enjoyed by these creatures. The adult is never
seen in the course of progression. Indeed, I doubt if its advance would
be perceptible ; but the young hydra withdraws unnoticed from the parent :
and in event of successive or of a series of generations, the whole indivi-
duals constitute a colony dispersed around its original founder. Their
segregation generally tends upwards.

Keeping this latter fact in view, it will be discovered that the like
general principle governs the compound zoophytic tribes : the increment
of the Sertularia is by ascending from the original cell giving birth to
the whole.

Spite of advancing multiplication, numerous colonies of the hydra
remain concentrated within narrow bounds. Though some adults seem
almost constantly rivetted to the same spot, it appears essential that the
young germinating from the parent's side shall be capable of removing, to
leave room for more, as propagation is incessantly going on. After ad-
vancing in one direction, they sometimes recede a little, slowly and
imperceptibly.

Thus the perceptions and active faculties of these creatures are ex-

80 ZOOPHYTES.

ceedingly obtuse, imperfect, and limited, farther than seizing and raven-
ously devouring whatever prey they can master. From this, perhaps,
they are always of small dimensions, when recovered from the sea. But,
by plentiful supplies of food, and frequent renewal of their native element,
they may be infinitely enlarged ; and they can be preserved several

years.

With age and increment the figure of the animal is considerably
modified, then becoming more elongated in proportion to its extreme dia-
meter. A colony under temporary abstinence is beheld in the most inte-
resting form, displaying so many pencils waving like tresses among the
water.

The peculiar habitation of the trumpet hydra seems the inner surface,
and especially the upper cavity of empty oyster or other bivalve shells. If
to be identified with the Hydra gelatinosa of Miiller, a colony occurred to
that distinguished naturalist on the under side of a marine fucus.

The oyster is very abundant in some parts of Scotland. The suspen-
sion of the hydra in its shell, together with intercepted view from the
profuse vegetation fringing the edges of many, may account for it so long
escaping the notice of observers. It difluses any where, however, pro-
vided the position be favourable, and certainly best where pendent under
shelter. It is obvious that a great colony on the lower valve of a large
shell, afterwards described, must have been most likely preserved from
some peculiarity, such as the shell resting at an inclination so as to allow
the action of the tentacula.

Notwithstanding all this, it will be seen in the course of the follow-
ing narrative, that the position of the original founder of the colony must
be accidental, times out of number ; and that the dispersion of the pro-
geny is dependent on the place of the parent.

The shell of a serpula bearing a group of hydrse was detached from
its fixture on an old oyster shell, and suspended by a silk thread passed
through the empty tube on the 21st of November.

In three weeks, this group proved to be in fine condition. It con-
sisted of three large specimens of a beautiful orange colour, and of seven
smaller ones, dingy white.

HYDRA. 81

Enlargement of the whole against January showed the advantage of
their new position, where the height of the shell sustaining them had been
so adjusted that food at the bottom of the jar was attainable by their ex-
tended tentacula.

The group had augmented to 25 on the Ist of April, when a fragment
of the shell, with seven individuals, accidentally separated, leaving the
other 18 adhering to the suspended portion. This latter alone continued
under observation, the fragment being abandoned.

Supervening changes and a series of other accidents befell the group
from the fragility of the shell. Portions of the surface, yielding in decay,
carried off the animals adhering to them. But in August of the following
year, or about 21 months from the commencement of observation, the
group was crowded and beautiful. — Plate XIII. fig. 2.

The greater proportion of the whole separated seven months later, in
April, and at length only six remained adhering in two years and a half
from the beginning. One of them, if not belonging to the original ten,
was of the first generation. The last of these six was detached in the
following June, or in 32 months from the November first specified, when
the shell proved so brittle that it crumbled to the touch.

Though many individuals which had formed the bulk of the group
were preserved, their history, as a community, was prosecuted no longer.
It is not that condition which admits the satisfactory elucidation of
details.

The anatomical structure of the hydra proper has been as yet but in-
sufficiently explained. In as far as I am informed, no muscular formation
is ascribed to its parts, though certainly endowed with muscular powers :
nor has any nervous or circulatory system been detected, though life and
sensation be evident in the remotest extremities. Some have lately af-
firmed the existence of ova or their rudiments, thus reviving an earlier
opinion, indeed the earliest of all, omne animal ex ovo. But I understand it
to be a desideratum on the whole, among the most skilful naturalists, that
many assertions were confirmed by undoubted experiment and observation
anew.

Confining myself, however, to the origin of this marine hydra, and
VOL. I. L

82 ZOOPHYTES.

the mode whereby it multiplies its kind, with the view of explaining the
increment of the arborescent zoophytes by the latter, I shall offer a few
definite remarks on the subject.

Propagation. — The faculty of perpetuating its race — that is, of beings
precisely similar to itself — resides in each individual of the Hydra tuba.
To that extent we would pronounce it a perfect creature of the same con-
sistence and form from its earliest origin as derived of a parent hydra ;
and its descendants, derived in the same manner, are identically so down
to distant generations.

In as far as may be judged, the perpetuation of the species — that is,
of the hydraform species — is an irresistible result of mere existence, a con-
sequence over which the individual hydra is not known to have any con-
trol, more than the individual vegetable has over the swelling bud or ex-
panding blossom. Neither is it evidently dependent on age, at least in a
general sense ; for we can scarcely pronounce on that period when even
a nascent individual is immature.

Let us assume, in the first place, an adult. If preserved in a suitable
situation, supplied with food, and its renovated element in purity, an em-
bryo speedily germinates from the side.

Thence it is natural to conclude that a germ, or depositation of ele-
mentary matter, subsists somewhere in the flesli — that, generated within
as a compact substance, its way is made, by a regular process, to the ex-
terior, where it becomes visible as a rising prominence.

Almost the whole of this animal's body is occupied by the stomach,
which swells from the disc to the apex when distended with food. All
reproductions or germinations necessarily ensue from its vicinity, and it is
singular how much propagation is promoted by abundant sustenance, as

already noted.

The embryo literally buds from the side of the parent as a simple
protuberance, frequently accompanied by a long fleshy spur with an en-
laro-ed extremity. Its use is uncertain ; nor is it permanent. But its ex-
istence seems solely dependent on the progress of reproduction ; and as the
early embryo advances to a later stage it disappears. This spur is previously
endowed with voluntary motion ; it curves and alters its direction readily,

HYDRA. 83

from being quite flexible. It is seen of various dimensions ; one half an
inch long, and of quantum equal to six tentacula, has issued from the base
of a young hydra still connected with the parent.

In the course of a series of observations on the progress of reproduc-
tion, I detached an adult from its site, on April 23, and deposited it in a
watch-glass, where, owing to favourable circumstances, it soon adhered.

In four days, a spur issued from one side of the base, and a large pro-
tuberance with a row of papillae, an originating embryo, was rising from
the other. — Plate XIII. fig. 3. Parent, a ; embryo, b ; spur, c. All as
on April 27.

On May 2, these papillae had elongated into perfect tentacula, like
those of adults, when both the parent and the offspring were fed. — Fig. 4.

Another protuberance on the opposite side of the parent was now
visible, either obscuring the spur or incorporated with it, which protube-
rance, gradually maturing as a young hydra, was fed on May 17 ; and the
subject, as consisting of three perfect animals and a spur, was delineated
on May 21. — Fig. 5.

The parent and the progeny were still connected ; but in other three
days decisive maturity of the latter appeared by the separation and esta-
blishment of three members of the cluster as independent animals.

It must be understood that, in earlier stages, the body of the parent
and the embryonic germination constitute a common integral mass ; but
as the uniting apex, or real basis of the embryo, is continually refining and
diminishing, it remains very slightly connected with the parent. Farther
security is therefore obtained by adhesion to some solid substance — here
the watch-glass ; then the offspring receding imperceptibly until united to
the parent only by a slender ligament, its rupture or disappearance sepa-
rates them for ever.

About May 24, the three specimens, a, h, c, were ranged in a straight
line. At a previous period they would have been comprehended in a
spherical triangle. Two protuberances, e, f, appeared on the opposite sides
of the parent, a, with a spur from e. A prominence also rose from 6 ;
c showed nothing. But on May 29, a small hydra, d, which had origi-
nated from c, was established between b and c. A very slender ligament,

84 ZOOPHYTES.

scarcely perceptible, still connected the animals, a, b, c. Of these two latter,
f, b, the larger was c, the younger having perhaps got more food. Next
day, May 30, the group appeared as in Fig. 6.

Within a fortnight, that is, on June 12, the whole group, from its new
accessions, consisted of the earlier three, a, b, c, now far apart, and of d, f, i,
being six in maturity. Besides these, a large protuberance, g, was issuing
from the base of a, the previous site of e, or nearly so ; which last, e, had
detached itself, and was abandoned. A protuberance likewise rose from
c— Fig. 7.

A seventh perfect hydra had come from one side of c, on June 16 ;
and in four days the colony consisted of eight.

The number of independent animals still continued eight on July 7.
But concomitant changes prognosticated the difficulty of observing their
progress much longer. Reproductions from each of the whole, were ad-
vancing, and particularly conspicuous in the larger, a, b, c Some of their
embryos exhibited the rudiments of tentacula ; and spurs, which generally
distort the specimen, were visible on the other five. — Fig. 8. The eight
perfect animals are a, b, c, d, f, (/, h, i.

On the 21st of July, or within three months, the specimen, fig. 3,
distinguished only by a spur and a protuberance, on April 27, had 15 de-
scendants, the whole having germinated from itself and its progeny. One
or two others were lost by separation. Thirteen, all of various age and
dimensions, were dispersed in adhesion over the cavity of the watch-
glass, and two lay below. — Fig. 9.

Some, such as d, d, had subdivided ; others were still connected by a
ligament.

Now it appears that a, the original parent, was the lowest of the
group.

But the progress of this colony could not be conveniently prosecuted
farther, for the watch-glass, obscured by the muddy deposit of sea-water,
precluded distinct observation. The slight adhesion of the young, as well
as of their progenitors, proved an invincible obstacle to attempting its re-
moval and purification. Therefore this group was abandoned.

Many objects, originally clean and beautiful, become foul and disco-

HYDRA. 85

loured, by the mud usually suspended in sea- water, especially if taken from
the flowing tide. Although this be ultimately productive of much embar-
rassment to the observer, its presence is so beneficial to various creatures,
such as the tunicata, vermes^ annelides, and others, that then they evi-
dently thrive, while declining, from its absence, in pure and limpid water.
Inadvertence to the fact, I believe, has cost me some valuable specimens.

Under such circumstances, inevitably supervening as in the preceding
tedious course of observations, the watch-glasses should be kept in vessels
comparatively of considerable capacity — in those containing perhaps from
four to six or eight ounces of water. Also, they should remain in an in-
clined position, the convexity outwards, so that the tentacula of the ani-
mals pendent within shall have free scope below. Thus the muddy depo-
sit, falling on the outside, admits of removal, whereas falling within, the
hydrse are liable to injury by attempting it. The observer will find it
more difficult to provide against obscurations and interruptions from the
insensible residue after feeding the animals, forming a glutinous adhesion
to the glass. Then the careful application of a feather, or a hair pencil,
will be found useful.

Sometimes several germinations develope into perfect hydrae, the
whole remaining united to the parent.

A solitary animal having been set apart, it subsequently displayed a
family of four well-grown individuals issuing from about the base, to which
they still adhered. — Plate XIII. fig. 10. In a week, the evolution of an-
other had ensued ; and the formation of two buds, with a serrated margin,
besides fig. 11. Original parent in figs. 10, 11, a.

After undergoing several changes, accompanied by the increase of
numbers, this group chanced to be committed to a vessel containing an
Actinia, in the confidence of that indemnity to be expected from the quies-
cent habits of a kindred race. Yet it was devoured.

Multiplication advances rapidly under the favourable conditions of
genial temperature, copious sustenance, and the element frequently reno-
vated. Did they often concur, we should more readily discover colonies
of these animals in Scotland. Further elucidations of their history will
surprise naturalists at their rarity.

86 ' ZOOPHYTES.

A specimen having detached itself from the group represented,
Plate XIII. fig. 2, adhered to the side of a jar, and showed symptoms of
reproduction on June 26. — Fig. 12. In a week, further developement
had followed, fig. 13. By successive evolution, this new subject consisted
of the parent and five young sprung of it, on July 15. Twelve individuals
with tentacula composed the colony on August 12 ; and twenty could be
distinctly enumerated on the 1st of September. But it is singular that
the parent hydra, a, as in a preceding example, was now the lowest on the
side of the jar ; all its progeny had withdrawn somewhat higher — several
considerably so. — Fig. 14. On November 22, they had augmented to 32.
About two years subsequent to the fixture of the parent hydra, fig. 12, to
the side of the jar, the colony, after many losses, consisted of 45. Such
losses are almost inevitable. The longer the period, the greater the chance
of deperdition among a number of objects.

One of this same colony having dropped from its site in October, I
transferred it to a watch-glass, which, after the animal had fixed, was kept
in an incliaed position, with the convexity upwards. In two months, nine
young were generated, and on the first of March following, the augmenting
colony consisted of 33 perfect hydrse, almost the whole being established
distinctly and separately.— Plate XIII. fig. 15. Their number would have
been greater had they not been fed rather sparingly, for the purpose of
obtaining satisfactory delineation. Here was a rare example of not one
being lost ; and the concavity of the watch-glass, whence the colony was
suspended, having been constantly downwards, it remained quite clean.
In another month, the number reached 47.

The multiplication of these creatures, by the budding of each succes-
sive generation of the progeny from the side of its immediate parent,
brings distant descendants into cotemporary existence. The accumulated
multitude originating from a single hydra, can be neither foreseen nor
estimated. It must depend on the duration of life and the rate of fertility.
We are ignorant of both. There is no reasoning a priori of what shall be

definite.

As the enlargement of the Sertularia advances, on corresponding
principles, where the hydrse, or at least many of them, enjoy some better

HYDRA. 87

shelter in cellular cavities for temporary retreat, it is evident that the
more luxuriant specimens may consist of thousands.

It is impossible, I say, to anticipate the progeny to come of a single
hydra. Propagation seems incessant. I cannot affirm that, as among a
multitude of the inferior animals, it is dependent on the seasons. No
doubt, there are conditions restraining multiplication ; but some of them
are not yet understood.

On November 21, just two years after the group, Plate XIII. fig. 2,
became the subject of observation, a specimen which had dropped from it
was found adhering to the side of the vessel. Four or five embryos were
now generating from the side of this hydra, which, being one of the largest
size, had doubtless given birth to many previous descendants. In April
following, the parent and its progeny had augmented to 20 independent
hydras, each affixed by its own apex, besides some others, still attached to
those from which they were originating. The number amounted to 50 on
July 23, when a, the parent of the colony, that is, of the four or five em-
bryos on November 21, was much larger than any of its progeny. But in
a month it appeared quite distorted, from a new budding of several more
embryos unequally advanced. A year after having established itself on
the side of the vessel as said above, its descendants — some of the second,
perhaps of the third generation — amounted to 73. The size of the parent,
a, still predominated over that of any of them except of one, b, which from
being fed equalled it. On the 6th of December, 83 were enumerated ;
and in addition to this great and rapid increase from one individual, the
colony afterwards augmented proportionally.

The size of the hydra, b, which had equalled that of the parent, a,
on November 21, now surpassed it on December 6, and young were bud-
ding from its oifspring. The voracity of this creature rendered fish, and
flesh, and all other animal substances gratefiil, for it was excessive. Por-
tions above its own ordinary dimensions were absorbed at a single meal ;
consequently its bulk enlarged over that of a, fed more sparingly. The
body, from repletion, swelled to at least thrice its ordinary diameter ; and
the animal adhering to the bottom of the vessel, not being suspended

88 ZOOPHYTES.

above, fell over in a flattened form, as if incapable of sustaining itself up-
right. It would remain thus during two or three days at a time.

According as the food is absorbed in the system, or as its residue is
rejected by the mouth, the symmetry of these animals is restored.

It is not surprising that distension from inordinate voracity should
strain the narrow point of adhesion by so small a surface, and separation
ensue. But the effects of repletion are different on the hydra and actinia,
though, in many respects, they be much akin. The tentacula of the acti-
nia are then finely displayed, as if having enjoyed its repast ; while those
of the hydra remain closely contracted, fig. 16, and the body is distorted
as if suffering from immoderate indulgence.

Though the natural colour of the Hydra tuba seems dingy white,
and always resolves into it, and though sometimes of orange or reddish
tinge when recovered from the sea, the quality of the food affects the hue,
and this for a considerable time. For example, specimens having fed on
the Gordim maximus, a large black or purple worm, continued darkly
stained for even two months afterwards.

Both the aspect and the fertility of the animal depend on its treat-
ment. Nevertheless, many irregularities occur which cannot be traced to
definite sources. The number of external organs is frequently very variable
in some of the lower animals, and in none more so than the genus hydra,
where the character of all they have is similar. The finest adults of the
subject before us have at least 30 tentacula ; but one of the largest size
had only 16, while a young one, its progeny, still adhering to the body,
was perfectly mature. The parent of a group of four had 20 ; the farthest
advanced 16 ; and each of the other two had 12. The specimen, Plate XX.
fig. 7, n, had just 16 in four months after representation there; nor could
I find that the number had increased in three months longer. However,
the original complement of tentacula, as will be seen of the originating
hydra from another form, is two or four, advancing to eight and upwards.
As copious sustenance promotes fertility, some of the most numerous
of the preceding colonies might have been doubled by unremitting care.
The mode of propagation which I have described does not, in my

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HYDEA. 89

apprehension fall strictly under the character of fission or cleaving, but is
more properly to be distinguished as (/e?iimation. By fission we under-
stand the division of a substance, each portion separating or caiTying off'
a part of the original whole, which is scarcely applicable to the forma-
tion of a bud from the parent's side.

Whether the budding results from a germ come of an earlier prin-
ciple, whether from the depositation of matter immediately secreted from
the substance of the parent, probably the primordial elements of the sub-
ject nasciturus — of that being which is to exist by developement, are the
same. All the works of Nature apparently resolve into great simplicity.
The preceding observations had been the occupation of many years.
But various facts and ambiguities still remained for explanation. The im-
measurable field, replete with animated beings, is such, and the portion to
be traversed by an individual attempting to journey over it so limited, be-
sides so many unavoidable obstacles in his course, he must often halt for
repose and opportunity. Thence no one has been yet found capable, of
himself, for composing the perfect history of any single living subject as
proceeding from the hands of the Creator.

There is none of Nature's products which should be more common
than the Trumpet Polypus ; still it is not so. To seek for it purposely is
vain ; in truth it is of rare occurrence.

A group obtained in the middle of August had been comparatively
neglected as of no farther use, but new circumstances of curiosity induced
me to restore it to suitable treatment, on the 10th of September, for per-
manent observation.

This group consisted of ten small hydrse, occupying the cavity of a
fragment of the Solen siliqua, or razor shell. They enlarged speedily by
feeding, and the invigoration of renovated water, so that in five or six
weeks they became sufficiently adapted for the object I Jiad in view.

In process of time these animals spread over to the back or convexity
of the shell, thus investing both surfaces by their multiplication and dis-
persion, during five or six months subsequently. — PI. XIV. figs. 2, 3. In
June following, or ten months after procuring the group, I found the co-
lony on both sides, consisting of 50 independent animals ; at least six
VOL. I. M

90 ZOOPHYTES.

others had dropped from their site. Many are thus lost with the lapse of
time, and some are also dislodged accidentally. In about two years, or
little more, from the commencement of observation, when the number was
ten only, the whole consisted of about sixty hydrse remaining, and now
dispersed over both surfaces. In two years and a half, however, those
adhering to the shell were reduced to nine, disposed on the sides towards
the lower edge.

Gradual decay and deperdition still impaired their number, for the
shell became very brittle with age, and it is this, amidst other inconve-
niencies, that aggravates the embarrassment of watching the progress of
subjects.

After repeating several incidental observations, previously made on
mutilated organs, I considered it necessary to ascertain more decisively
the kindred nature of this hydra of the sea to the fresh-water species of
Scotland, so as to warrant its incorporation or otherwise with the same
genus.

I do not recollect that naturalists have ascribed the property of re-
covering lost organs to any but perfect animals : for, if I be not mistaken,
the numerous experiments related of regenerated parts, were made on
those in their ultimate stage.

Nevertheless I confess myself extremely averse to such experiments,
though no such tender scruples are entertained by others. Besides, where
practicable, it is better that our studies should be confined to animated
beings unconstrained and uninjured.

About the middle of October, or six weeks after new treatment had
improved the group on the razor shell, the specimen, PL XIV. fig. 1, a,
was bisected. In a fortnight, a row of regenerating tentacula extended
two lines from the stump or under portion ; and in another week the
mutilated animal had become entire. It was delineated on February 13,
or four months from the date of the experiment, along with its com-
panions, all in the cavity of the shell, being seen at that time as above
quoted, — somewhat exceeding nature — a, fig. 1, PI. XIV. There it
remained unchanged, but much enlarged, eleven or twelve months after
bisection

HYDRA. 91

Other two specimens were next subjected to similar experiment, —
PI. XIV. fig. 3, a, and fig. 3, b, — ^both being on the convexity of the shell.

The former, a, which is represented separately by fig. 4, was bisected
with very sharp scissors, on March 12. The stump is seen, fig. 5, as re-
maining in its place after bisection.

In a fortnight, this stump had generated about sixteen long silky ten-
tacula, fig. 6 ; but neither extending so equally nor preserving such regu-
larity as shewn by specimens entire. However, they continued advancing,
and the stump to which they belonged became a complete animal ; when
it was accidentally lost, along with some of its neighbours, above a year
after the group had come under observation.

So much for the under half. In regard to the upper half, severed
from fig. 4, that is fig. 3, a, bisected as already said on March 12, the
wound had healed when delineated with the original tentacula, on March 29,
fig. 7 ; enlarged, fig. 8. Thus two perfect animals resulted from the bisec-
tion of one.

But this last, fig. 8, subsequently exposed some peculiarities. Its
tentacula were nearly but not completely obliterated. Several short, ob-
tuse prolongations, unlike originating tentacula, next appeared on the 6th
of May. The subject had undergone much alteration on May 25, then
consisting of many obtuse parts, as more distinctly seen when enlarged. —
Fig. 9. Farther alteration alike singular had ensued on the 5th of June,
fig. 10, at which time these anomalous parts extended as tentacular organs
of very irregular length and form. Some were long and slender like ge-
nuine tentacula ; others thicker and shorter : but there being a constant
tendency of nature to produce or to restore symmetry, the whole were
approaching the proper shape in 16 days, or on June 21. — Fig. 11. This
refined still farther, figs. 12, 13, as on August 21 and 29, when perfect
symmetry had been acquired.

It still remained to be seen whether so great a mutilation as priva-
tion of half the body, which this subject had undergone, was now com-
pletely redintegrated, in as far as to carry on all the purposes of existence.
Time alone could prove it ; and the fact] was at length verified indubitably
by the gemmation of progeny from its side, and separating to enjoy inde-

92 ZOOPHYTES.

pendent life. — Fig. 14. A young hydra, only a prominence on Septem-
ber 1, had withdrawn on the 21st. — Fig. 14, a. It had eight irregular
tentacula in an earlier stage, and was connected by a ligament to the
parent.

It Avill be preserved in recollection that the subject just described was
the upper portion sundered from fig. 4, or what is originally named as
fig. 3, a.

Pursuing the history of its companion, originally fig. 3, b, or fig. 15,
\vhich is the same as represented singly, an intimate correspondence will
be found with that of the preceding subject as to the leading featui-es.

The stump, fig. 16, remaining after bisection, had regenerated about
12 tentacula in a fortnight. — Fig. 17. The number of these, together with
the dimensions of the stump, gradually augmented, and the whole of this
mutilated portion became subsequently a fine and perfect specimen, giv-
ing birth to progeny.

It is therefore unnecessary to say more of the stump, fig. 16, the
lower half of fig. 15.

But in regard to the upper half of fig. 15, or fig. 3, b, severed on
March 12, it appeared with its original tentacula on March 29, as repre-
sented fig. 18 ; enlarged, fig. 19. Their irregularity was then conspicuous.
Only their tips were visible on April 25 ; and soon after, these were
totally obliterated.

This subject remained a shapeless mass on June 21, as represented
fig. 20, at which time it had not affixed itself to the watch-glass wherein
it lay ; neither had it done so a fortnight later. The change was great,
nor could I then account for it more than for the numerous prominences
distinguishing the former subject, fig. 9, originally the upper half of fig. 4,
or fig. 3, a

But on July 23, there was an obvious alteration of fig. 20 advancing,
for it now exhibited several irregular tentacular organs spreading from
the surface. — Fig. 21. The whole shape improved progressively ; and on
August 9, it had grown quite symmetrical, with a due proportion of silky
tentacula. — Fig. 22. It was a perfect animal, in as far as regarded the
birth of progeny, for within twelve days a young hydra, first budding from

HYDRA. 93

its side, had removed to some distance, fig. 23, a ; and while this young
hydra, a, was advancing, another, b, had also withdravra. Meantime, a
new bud germinated from the parent, c, then entire, which continued to
propagate. — Fig. 24.

Thus the upper portion, sundered from the specimen Plate XIV.
fig. 15, may he traced through figs. 18 (enlarged, 19), 20, 21, 22, 23, 24.
The first, fig. 18, representing that mutilated fragment : the last, fig. 24,
representing the same fragment 150 days later, completely redintegrated,
and generating a new colony.

As the stumps, or under halves of fig. 1, «, of fig. 3, a, and of fig. 3, Ij,
which had all three suffered bisection, by removing the upper part, re-
mained adhering, I say, as all three subsequently regained tentacula, and
became the parents of future progeny, the reproductive faculties residing
in them, not only for the restoration of lost parts, but for perpetuating
their race, were not extirpated by such an excessive mutilation.

It may be remarked here, besides, that both the sections of the same
sundered animal having generated progeny, demonstrates one of two facts,
— either that all the embryonic elements are not concentrated in a single
point, which would restrict their evolution as hydra; to one of the sections
only ; or that the elements of the progeny are secreted and deposited pos-
terior to mutilation, to be evolved by gemmation at a suitable period.

No important injury had, therefore, followed bisection ; for both
portions grew, and fed and bred in the same manner as entire animals.

The preceding narrative proves, /^-aV, That redintegration of the organs
defective in the Hydra tuba, follows precisely as after mutilation of those
species of the hydra proper dwelling in the fresh-waters of Scotland.
Second, That the elements of the progeny, whether in a primordial germ,
or secreted and deposited from the parent, are neither restricted to a single
point nor to one half of the body. Third, That both the stump below, and
the section above, becoming entire animals, alike complete, by the evolu-
tion of new organs, and the preservation or acquisition of the faculties
essential for the living creatures, the name and character of hydra had
not been misapplied.

I speak of general results and appearances, for in a long course of

94 ZOOPHYTES.

observations, certain anomalies and peculiarities interposed, which I can-
not pretend to explain, nor can I even describe them intelligibly.

I might offer some vague hypotheses, indeed, trusting to futurity for
their verification.

But maturely reflecting on that obliteration of the old, which was
followed by the developement of new tentacula in fig. 20, I cannot
avoid conjecturing it the effect of disturbing the progress of the wonder-
ful alteration incident about the same season to this animal, as shall be
afterwards illustrated. Let us remember that fig. 20 was the upper half
bearing tentacula, sundered from fig. 15. Most probably by repeating the
experiment in the course of March some light would be thrown on the
subject.

Farther, in 17 days after severing fig. 8 and fig. 19 from their re-
spective stumps, the former being the upper half of fig. 3, a, the latter the
upper half of fig. 3, b, four ribs were rising from the circumference of each,
and extending obtusely beyond the base. Irregular intervals separated
the ribs.

A very slow horizontal motion was exhibited by fig. 20, at the period
of delineation. Likevsise two white fleshy corpuscula present, like fig. 25,
were in slow horizontal motion. I could detect no external organs in-
fluencing them.

We have already traced the history of the sundered portion, fig. 18,
being the upper half of fig. 3, b, as there represented on March 29, down
to its aspect on September 29, as represented fig. 24, c.

Following it as then regenerated yet a little longer, it appeared in
another week vdth the stomach completely everted, as sometimes occurs
to the Actinia. But in two days this was returned to its proper place, the
natural shape resumed, and the tentacula extended in regular order.

Two months subsequently, however, the whole tentacula dropped off
in a bunch, without any obvious cause, and carrying a small portion of the
body along with them. Next morning, this detached part resembled a
small hydra crowned by irregular tentacula, remaining so for three weeks,
when adhesion in a watch-glass had taken place. These organs amounted
to twenty at least. The body thus naturally mutilated of the bunch and

HYDRA. 95

fragment continued in its place ; it became an elongated ovoid, and in
three weeks had generated 12 or 14 tentacula, after which farther obser-
vation was abandoned.

In regard to this animal (the Hydra tuba), its propagation seems
more dependent on sustenance than on age and dimensions. The number
of organs is invariable in the higher orders, subject neither to multiplica-
tion nor diminution, unless to an inconsiderable extent where regenerated ;
but in the lower orders the discrepance is so great as generally to preclude
the determination of maturity by such a test.

The aspect of the hydra is considerably diversified. In perfection it
is a pendent cone, or rather the gradual enlargement of a conic frustum,
the margin of the base environed by long silky-like tentacular organs.

But the shape of the most vigorous is liable to some modification.
The disc, with the marginal tentacula, can enlarge beyond the wonted
diameter, and assume the resemblance of a flattened hand-bell, suspended
by a slender thread, while all the portion above it is diminished. —
Plate XIV. fig. 26 ; XX. fig. 19, a. This generally results from the sen-
sations of an individual, but I have seen a number at once under the same
appearance.

The preceding examples in illustration of the multiplication of the
hydra, offer some anomalies when compared with that of other animated
beings.

Amidst the functions annexed to protracted existence, scarcely any
except those which are essential for self-preservation are passively or ac-
tively incident to the earlier stages of life, and especially in such creatures
as shall finally acquire another and a different form.

Perpetuation of the race seems to be reserved by Nature, in general,
as a property incorporated with that ultimate condition wherein all the
organic evolution has been attained, wherein all the animal faculties sub-
sist, and are exercised as indicative that the system is perfected.

I am not aware that progeny is derived from animals in intermediate
stages — in those to be compared to the larva or the chrysalis, but that the
offspring comes of the beetle or the butterfly, as the ovum from the frog,
not of the tadpole. It is not said that an embryo or foetus is endowed with

96 ZOOPHYTES.

any other than the passive faculty of merely receiving such nutrition as
shall promote its own advances towards maturity.

Whatever be the common rules adapted to strike the senses, neither
age nor dimensions will prove perfection, both being relative characters.

The hydra perjDetuates its race after principles adverse to those usual
arrangements of Nature, of which we are enabled to judge. Its progeny
is originating at the earliest visible stage of the parent, and this progeny,
while still incorporated with that parent, is giving birth to offspring. The
descendants to a remote generation are in the exact resemblance of the
original hydra, their progenitor. They inherit its form and its properties
unchanged.

My observations on the group investing the shell of the Solen, were
continued as far as practicable, during two years and eight months : and
on another colony and its descendants, they were continued for six years.
Many specimens have been assumed and preserved besides, on different
occasions, during the last twenty-three years at least.

From what has been said, the mode of increment, whereby the Sertu-
larian and other compound zoophytes are augmented, will be the more
easily understood, making some allowance for the diversities of structure.

The following conclusions may be deduced from the preceding nar-
rative : —

I. The nature of the Hydra tiiha is nearly identified with that of the
hydra or polypus of the fresh-waters of Scotland.

II. The body consists of a dilatable conical sac, with a marginal row
of tentacula around the disc, which are capable of extending five times
the length of the body.

III. It feeds voraciously, and like the Actinia, rejects the undigested
residue by the mouth, which is in the centre of the disc.

IV. It can endure long protracted abstinence, under which the size
o-radually diminishes, but is suddenly restored by sustenance, and it sur-
vives during years.

V. It is extremely prolific ; and propagates by gemmation or the
budding of the offspring from its side.

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HYDEA. 97

VI. As the offspring withdraws from the parent, a connecting liga-
ment is gradually attenuated, and at length ruptured, as in certain species
of the Actinia.

VII. If rupture of the ligament be protracted, cotemporary progeny
may continue budding, both from the body of the parent and from that of
the offspring.

VIII. The elements of the progeny are not concentrated in a definite
spot of the body of the parent.

IX. The hydra is very tenacious of life ; it is endowed with power-
ful regenerative energies. It survives the severest wounds and lacerations,
and reproduces mutilated parts.

X. It is endowed with a locomotive faculty, which is very rarely ex-
ercised by adults ; and chiefly demonstrated by the young.

XI. Its natural and favourite position is suspension by the apex, al-
lowing the free extension of the tentacula.

XII. It dwells in numerous societies, or lives in a solitary state.

Plate XIII. Hydra tuba. Trumpet Polypus (Strolila).
Fig. 1. Adult ; body, a ; tentacula, I.

2. Colony investing an old shell of a Serpula.

3. Adult, a ; embryo budding from it, b, spur. — April 27.

4. The same farther advanced ; adult, a ; embryo, h ; spur, c.

—May 8.

5. The same ; embryo, I ; spur, c ; both now perfect hydne,

still connected with the parent, a. — May 25.

6. The same augmented by new gemmation ; the offspring

withdrawing from the parent.

7. The same colony farther dispersed. As a, 5, c, here, and

of the preceding figure separated, new animals, d,f, i,
were interposed. — June 12.

8. The same colony, consisting of eight perfect hydrse, besides

embryos. — July 7.

9. The same according to its final arrangement and aspect

while remaining in distinct view. Some hydra, previously
single, d, i, have now generated others, d, i. — July 21 .
VOL. I. N

98 ZOOPHYTES.

10. A group consisting of the parent, a, and its progeny of

four still connected with the body.— ilfay 8.

11. The same, with a sixth hydra originating.— ilf ay 15.

12. A hydra, a, with indications of reproduction. — June 26.

13. The same, the reproduction having advanced. — July 3.

14. The same hydra, a, now the lowest of the group, all the

progeny being above it. — Sept. 1.

15. A specimen, a, which was single in the middle of October,

represented shortly afterwards in an intermediate stage,
fig. 19 ; and as now seen with its progeny, generated sub-
sequently.— March 1.

16. A hydra gorged with food, the tentacula contracted.

17. A hydra adhering to the bottom of a vessel. Distorted

prominences announce reproduction.

18. The same, farther advanced.

19. The colony represented fig. 15, here seen in an intermediate

stage, between October, when there was only a single
hydra, and the month of April subsequent.

20. Colony generating from a hydra.

Plate XIV. Fig. 1. Colony of the Hydra tula occupying the concave frag-
ment of an old shell of the Solen siliqua. The hydra, a, had
been previously mutilated of the upper half, which was at
this date regenerated. — Feb. 13.

2. The same colony multiplied and dispersed. — March 12.

3. Another colony on the convexity of the shell, derived from

the former, fig. 1. — March 12.

Here the specimens a and b were selected for experi-
ment.

4. The specimen a, just referred to, as in fig. 3, viewed sepa-

rately as on that selection. — March 12.

5. Stump of fig. 4, remaining after the animal was bisected. —

March 12.

6. The same stump, fig. 5, having regenerated the upper part

with tentacula. — March 29.

7. Upper portion severed on March 12, from fig. 4 (originally

fig. 3, a) as now seen on March 29.

8. The same enlarged.

HYDRA. 99

9. The same enlarged as on May 25. — The formation altered.

10. The same as appearing June 21. — The prominences elon-

gated.

11. The same approaching symmetry. — June 26.

12. The same become more symmetrical. — Augmt 9.

13. The same upper portion, or fig. 7, quite symmetrical as

seen August 21.

14. The same with its progeny. — September 29.

15. The specimen, fig. 3, b, viewed separately on selection for

experiment. — March 12.

16. Stump of fig. 15, after bisection of the entire animal. —

March 12.

17. The same stump having regenerated the upper portion with

tentacula. — March 29.

18. Upper portion severed on March 12 from fig. 15 (originally

fig. 3, b), as seen on March 29.

19. The same enlarged.

20. The same, the tentacula being obliterated, enlarged. —

June 21.

21. The same, with irregular regenerating tentacula. — July 23.

22. The same, having attained symmetry. — August 9.

23. The same having generated progeny. — August 21.

24. The same with additional progeny. — September 29.

25. White fleshy corpusculum in motion. — 3Iay 25.

26. Hydra relaxing from its usual form.

§ 2. Origin of the Hi/dra tuba. — Plates XV. XVI. XVII.

Hitherto we have considered the hydra as a perfect and independent
animal, living for itself, and carrying on a race of beings, its posterity, in
its own likeness. But we have still to penetrate farther into its nature.
No doubt, some of the principal purposes of physiology are already ful-
filled, and the reader will not find it difficult to understand from the pre-
ceding detail, the precise mode whereby such accessions are gained by
Zoophytes as to render these productions of admirable luxuriance and
beauty. It will be seen how they may originate from a single individual,

100 ZOOPHYTES.

the parent of the whole ; that their progress is derived from the animated
portion alone of compound subjects, that which, to our apprehension, is ex-
clusively endowed with life, sensation, and action : for although what we
call the inorganic parts be indispensable, and form the instrument of the
general union and connection of all, nothing denoting active animal fimc-
tions is to be detected there.

The increment of zoophytes might have been explained as effectually
perhaps from the multiplication of the fresh-water hydrse. — Plate XII.
figs. 15-20, and the Vorticella, Plate XXI. But the superior dimensions
of the subject I have chosen, the facility of preservation, and the certainty
of witnessing its prolific qualities in the most convenient position, under
suitable, simple, and easy treatment, render it infinitely preferable to the
others. The chief obstruction to the wishes of the naturalist concentrate
in the difficulty of obtaining specimens, for there is no known guide which
can lead to their disovery.

The hydraoid zoophytes multiply in general by simple divergence to
rio-ht and left in the same plane, a character peculiar to most of the asci-
dian zoophytes also, especially of the foliaceous genera. At the same time,
multiijlication by ascent is advancing in both, whence may be compre-
hended the rapidity wherewith vigorous specimens shall reach to thou-
sands.

Strict conformity subsists between the increment of these and of the
Hydra tuba. The original parent remains, in all, the lowest of the colony,
or amidst the progeny diffusing around it. But there is one noted diffe-
rence not to be overlooked. The Hydra tuba survives the birth of its
own young, and also of their progeny, for some indefinite period ; but the
original parent of the Sertularia and the Flustra perishes as its posterity
continue increasing by successive generations.

However, I shall rather reserve for the conclusion of this treatise a
brief review of some leading principles governing the nature of such zoo-
phytes, as have led us into more diffiise discussion in its course.

Meantime, let us consider how vast the proportion of the lower
animals incorporated with the various hydrse in their more comprehen-
sive si"-nification ; that multitudes in one or other stage are connected

HYDRA. 101

with it in form or substance, sharing its intermediate nature. Further,
that to the creature which we recognize under this name is assigned a
most important province relative to the perfection and the perpetuation of
some tribes which we deem the farthest removed, those which occupy a
place altogether different in the order and arrangements of the universe.

Nothing is more frequently the subject of speculation among ordinary
spectators, than the clear or coloured masses of a gelatinous-like substance
strewed on the sea-shore, sometimes in great profusion, particularly towards
the end of autumn. They are left there by the falling tide, either entire,
of a circular form, or broken into fragments.

This is commonly called Sea-lluhber. I do not recollect to have
ever heard any other vernacular name applied to it in Scotland.

But here are beheld only the remains of the Medasn, a marine ani-
mal, alike curious and beautiful, which, in extraordinary variety, frequents
the Scotish seas.

In certain years they appear in thousands. It is not accurately as-
certained from whence they come or whither they go ; but they seem to
be dispersed over the whole world. In the year 1846, the fishermen told
me they were embarassed in casting their nets and sinking their lines from
the multitudes absolutely thickening the sea. Baster remarks their sin-
gular abundance on the coast of Holland in 1762.

In the course of a series of experiments and observations for investi-
gating the properties of these animals, I directed a number of very capa-
cious glass vessels to be made, where a complete view of their singular for-
mation and habits would be obtained while living amidst their native ele-
ment.

Then I took four fine specimens of the genus now established as the
Chrysaora of Peron, which, unless I be mistaken, is not distinctly noted
• among the profusion of synonyms occupying various general systems of
natural history.

This species attains large dimensions ; one of the four was sixteen
inches in diameter, and of several pounds weight, and hence less convenient
for observation than smaller subjects.

The animal consists of the segment of a sphere called the umbrella.

102 ZOOPHYTES,

convex above, and concave or somewhat flattened below. A row of long
slender tentacula descends from the circumference, which circumference
is divided into 32 lobes, each lobe being imprinted with a dark brown
patch speckled white. Four long frilled appendages of similar colour in the
solid parts, but lighter in the frills, hang down from the under surface.
Here also are four large cavities, each with an orifice converging towards
the centre of the animal, wherein the ovaria, resembling clusters of grapes,
are deposited. The whole surface is of different shades of brownish-yellow.
Selecting a specimen of this Medusa eight inches in diameter for
more minute observation, I lodged it in a clear and capacious glass jar on
the 24th of August. Herein the umbrella continued to collapse and to reach
the surface by impulse on the water, as these animals do naturally in the
sea. On gaining this position, the Medusa remained still and motion-
less, as if to be carried along by the flow or the ebbing of the tide. —

Plate XV.

After transferring the largest of its fellows to another capacious ves-
sel, I experienced very sensibly ihe noxious property ascribed to the race.
My hands and wrists suffered burning heat for several hours, spite of be- -
ing plunged immediately into cold water. It is thence that the Medusa
is called the Sea nettle ; and many accounts are given of the injury sus-
tained from contact with it in those seas where it abounds. I acknow-
ledge that I was long incredulous, especially because many may be handled
with impunity, and from distrusting fishermen, who are too often addicted
to exaggeration. A friend of undoubted veracity, assured me that having
come in contact with some Medusae, while bathing in the estuary of the
Forth, violent inflammation of the skin ensued, which was accompanied
by a serious attack of fever. I have no doubt, however, that several of the
most marvellous narratives have come from those persons who were more
alarmed than hurt, by finding themselves suddenly in so disagreeable a
neighbourhood as amidst a number of Medusse. It is not evident that
these creatures employ any of their external flexible organs purposely to

injure.

Although the specimen above quoted as eight inches in diameter
seemed sufficiently vigorous, it could be kept only a few days from decay.

V. I.

PL.XV'.

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HYDRA. 103

There seems a natural delicacy incident to the whole tribe in confine-
ment ; nor have I been able to preserve any adult individual above a month
in activity.

This specimen being removed from its vessel on August 25, a quan-
tity of brownish matter like dust remained at the bottom. Subjected to
the microscope, it proved an host of animated creatures in quick and varied
motion.

But to the naked eye they were hardly perceptible, — the merest
specks, infinitely minute, — nor by an ordinary lens could their propor-
tions be discovered.

Higher powers, next resorted to, shewed them white, opaque, and
fleshy, tending to an elliptical form, though very mutable, one extremity
generally broader than the other, with which each individual made its way
among the multitude of its fellows.

Although such be the real and natural figure of the animal in vigour
and perfection, some already betrayed incipient alteration in assuming a
broader oval, contracting middle, a globular shape, becoming a thick
spherical triangle, or exhibiting other irregularities. Nothing strictly an-
gular was seen among them.

All were crawling below with a quick, smooth, lively motion. The
body seemed consistent and soft, evidently yielding in pressure through
the crowd. No cilia or other external organs, though probably present,
could be detected ; for, perhaps the magnifying powers were insufficient.

On the whole the animals obviously participated of the nature of the
PlanulcB, above described as belonging to the Sertularia ramea, and of
the others whereof we have yet to speak, as the origin of many zoophytes.
— PI. XVI. fig. 2, enlarged ; fig. 3, magnified.

After the lapse of other forty hours, the subjects of figs. 2 and 3,
seemed of twofold composition, as consisting of a lighter margin now sur-
rounding a darker interior portion of corresponding form, — previously, the
whole had a uniform homogeneous aspect. The shape of others had also
become considerably modified ; but whatever the outline of the exterior,
that of the interior always corresponded : if the nucleus or inner darker

104 ZOOPHYTES.

portion was long, short, spherically triangular, or otherwise, so was the
marginal border, fig. 4.

The whole subjects inspected were at the bottom of a watch-glass ;
and all were yet in motion.

A gi-eat profusion of the brownish substance like dust had been dis-
charged by each of the four Medusae obtained on August 24. Next day,
August 25, six vessels, each containing a portion of it, were set aside.

In forty-eight hours, namely on August 27, the appearance of spots
of scum at the surface of the water in some of the vessels, announced the
progress of certain alterations below.

On applying these spots to the microscope, they were plainly dis-
covered to consist of the planulse in a state of advancing metamorphosis.
All remained still and floating. Some of the least altered approached a
shuttle-shape, with an orifice in the centre : the ends of the shuttle were
more prolonged in others, — several shewed obvious indications of four
incipient arms, in unequal progress, around the central orifice, fig. 5.

On the following day, August 28, a remarkable change had ensued.
The metamorphosis was rapidly advancing ; for the elongating arms pro-
mised to be of peculiar tentacular texture, fig. 6, as amply realized in
three days longer.

Now their extent equalled some diameters of the body ; — the two
from the ends of the shuttle remaining always more prolonged than the
others, figs. 7, 8. Both the subjects there represented as the most favour-
able for illustration, floated reversed when delineated, whereby the orifice
being below is not seen, and some of the tentacula, along with the upper
surface, are directed downwards.

All this was an extraordinary exhibition in the offspring of such pa-
rents— that so lately issuing as mere and almost invisible dust from com-
pact, massy, ponderous animals, alike singular in habits, in form, and in
substance.

But Nature had an important purpose to fulfil : the apparently rude
commencement had to be carried through, by wonderful expedients, to
symmetrical perfection in the end. In eleven or twelve days after the

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HYDRA. 105

simple active atom, — the planula had been discharged from the unwieldy
Medusa, it was converted to a stationary hydra !

This new animal was provided with a complement of eight arms, yet
80 immature as to be of unequal dimensions. Different groups, under
metamorphosis, shewed the utmost irregularity in respect to evolution, to
their shape, and proportions, figs. 9, 10 : nor was it until thirteen days later,
or three Aveeks after their birth, that any appeared with eight regular
tentacula.

Thus was a most perplexing problem solved — the Hydra tuba proved
to have sprung of a Medum.

The planulae of the arborescent zoophytes already described, and
many whereof we have yet to treat, are generated in external pods
or vesicles, from whence they issue when mature into active life ; next
becoming quiescent, and metamorphosing to the zoophyte . Here the host
of planulffi is contained in bunches of capsules reposited in the ova-
rian sacs or cavities above specified as belonging to the under surface of
the Medusa. The different capsules vary in size and in form — Plate XVI.
fig. 1.

There is no doubt of the planulae being originally ova ; and that their
evolution advances as in the vesicles of the arborescent zoophytes, or as
the rudimentary embryo retained in the capsule of the Tubularia.

I have seen a stream of cremacious-like matter absolutely flow from
the ovarian sacs of the Medusa, proving exclusively incalculable legions
of planulae.

Much irregularity prevails in everything connected with the history
of these animals. I cannot specify the longest period of activity by the
planula. I have observed some in motion during 18 days, and some, from
the Mcdma capillata, during 19 days. The latter always advanced with
the smaller extremity first, during progression, whether from natural
habits or supervening incident.

The metamorphosis of that species of the Chrysaora, the more par-
ticular subject of these observations, commences very speedily, often within
forty-eight hours, or even sooner, if the planula be kept still, which is es-
sential. But there is no uniformity either in progress or in perfection.

VOL. I. O

106 ZOOPHYTES.

In jirosecuting the investigation of this subject still farther, I have
availed myself of some very fine specimens of different species of the Me-
dusa at different times.

First, I took five specimens of a kind vphich I shall provisionally de-
nominate Medusa stella, from my inability to recognise it -with certainty
in the Systema, and afterwards six of the same.

All were of different dimensions, the umbrella of none exceeding fif-
teen inches in diameter, nor that of any under seven.

Perhaps this species has some affinity with the preceding, but it is of
more ornamental appearance. The animal is of a faint yellowish colour,
with either a brown spot or a circular ring on the summit of the um-
brella, at a short distance from which a fine and conspicuous star of
thirty-two rays is formed by the divergence of as many lines from points
commencing them. This configuration will be readily understood from
inspecting Plate XVII. Still farther outwards the margin is embellished
by thirty-two brown patches, and a row of long slender tentacula falling
from the edge. Four long flexible organs, with a double marginal frill,
like the former, originate from below, somewhat different in different sub-
jects. There are also four ovarian cavities below, each with a dilatable
orifice. The skin of these cavities is wholly covered by a singular speck-
ling ; and so is the whole surface of the umbrella speckled, but in a diffe-
rent manner.

From the stellate figure above, and the four appendages being at
some distance beneath the under surface, the animal cannot be mistaken.

The brown colour of these Medusae seems derived from a peculiar
matter. Sometimes the water wherein they die is deeply tinged.

All the eleven specimens were prolific. The sjjecimen represented
Plate XVII. having remained two days in a large glass jar, a brownish
circular stratum, two inches in diameter, consisting solely of myriads of
planulse, was found under its position, by removal to another vessel on
August 31.

Here the animal continued as in the last, rising to the surface, and
collapsing its expanded umbrella, while the appendages were allowed to
hang down to the bottom.

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HYDRA. 107

"V\1ien portions of the circular stratum were presented to the micro-
scope, I could not discover any difference between the planulse there and
those of the preceding Medusa. They were white, solid, elliptical, and all
in lively motion. Their extreme minuteness rendered the determination
of their exact form very diflScult by the naked eye.

Many of the planulne were now set apart in different vessels, to re-
main for a certain time undisturbed.

The progress of metamorphosis, on the whole, narrowly resembled
that of others, but perhaps with less irregularity, from the quiescence pre-
served ; and some interesting illustrative facts were disclosed.

One of the vessels, a narrow cylinder, six inches deep, being examined
in ten days, I found the water covered by a thick scum like cambric paper,
and so tenacious that portions had to be cut out by scissors for the micro-
scope.

Such portions proved wholly composed of metamorphosing planula*,
which were generally rounder, not so quadrangular, or rather so obtusely
cushion-shaped as the former ; nevertheless exhibiting considerable variety
of figure. Four originating tentacula had become evident in a few, and
in one of this description the distended orifice of the mouth exposed the
internal cavity below. — Plate XVI. fig. 15. No planulse now visible
were unchanged.

All these subjects seemed imbedded in the scum, or they were per-
haps adhering to the under surface of it, for in further progress many
might be seen hanging down, as if suspended from that surface.

The quantity of scum thus covering the surface of the water in the
vessels containing planukie is very great. An observer might readily con-
clude that its presence and profusion indicated decay. But it is not so. I
venture to conjecture that it may be more probably considered a conco-
mitant on metamorphosis.

At first the planulaj crawl at the bottom of the vessel : very few under
ordinary circumstances rise on the sides, nor are they to be often seen
swmming. But after some time, a scum is formed on the surface of the
most limpid element, even in tall vessels, amidst which they are motion-
less, in thousands. I know not how they rise, whether by some super-

108 ZOOPHYTES.

veiling buoyancy accompanying incipient metamorphosis, or whether by
ascending the sides. Frequently there are scarcely any remaining below ;
but numberless specks, denoting their presence, may be also sometimes
seen at the bottom, while the scum is composed of multitudes above.

Having shifted a Medusa of the former species from a capacious ves-
sel, I poured off almost the whole water, leaving innumerable planula?
among the residue. This residue being next emptied into another, a
smaller vessel, four inches wide by two deep, the bottom was entirely co-
vered by planulse. From the vast legions below I was apprehensive of
decay, however, all remained vigorous : and in three days numbers were
swimming throughout the water. In three days longer, the surface of the
water was overspread by a film resembling cambric paper, obscuring the
whole contents at the bottom. Extraordinary myriads of planulse were
in the vessel, so that, for more security, to avoid vitiation, and to give
the animals greater scope, by increasing the quantity of the element, and
to prevent interruption of the course of observation, I sunk this smaller
vessel in one of much larger dimensions, wider and deeper. As the latter
was gradually replenished, a compact circular scum, equalling the diameter
of the former vessel, rose entire and unbroken, composed wholly of
planulse.

Though I describe it as wholly of planulse, the scum consists also of
a large proportion of glutinous matter along with them, — another remark-
able provision of Nature.

The progress of that metamorphosis converting an animal of great ac-
tivity to one in a stationary condition, seems to be attended with the exu-
dation of a glutinous matter from the body. While active this would be
of little use, but now it is different in becoming the means of security.
Thus, where the animal occurs singly, and the change so far advanced that
it adheres, a slight diffusion around the extremity, or point of adhesion, is
perceptible by the microscope.

The secretion of this substance, I presume, is the origin of the tena-
cious scum ; and owing to the incalculable numbers crowding the surface,
the smallest quantity from each, would produce, when united, a compact
matter wherein they might be imbedded.

HYDRA. 109

The natural position of the hydra in maturity, being pendent, may
account for its tendency to rise upwards in taller vessels, "with the com-
mencement or the progress of the change.

As the advances of metamoi-phosis evidently depend on circumstances,
they must be attended with great irregularity. Many planulae decay with-
out any sensible altei'ation : in others the change advances tardily and with
difficulty : the difference of a fortnight's progress, or much more, will be
seen, in the state of two portions of the same brood at a given time ; and
in many, though great, it is never completed. But sometimes its progress
is distinct during the course of a long observation. I speak of the pro-
geny of JNIedusaj in general.

A nascent hydra may acquire eight tentacula within twelve days of
its birth from the Medusa. But amidst above a thousand specimens of
the same brood, I could discover only one with twelve tentacula in forty-
five days. — PI. XVI. fig. 14. Many others had then eight, which were
long and deeply muricate. But some had only four, quite as long, and
as deeply muricate. None ever gained more than twelve : nor of at least
two thousand hydrse, originating at first in a vessel, did any survive, in
seventy days from their production.

Unless in very favourable positions, it is by no means easy to follow
the history of such minute specks as those of which we treat.

The most convenient method of observation is when they are affixed
to watch-glasses. The progeny of the Medusae, while yet planulse, should
be transferred to a flat vessel, some inches in diameter, filled to any height
■vvith water. One or more watch-glasses may be then inverted above the
planulse, and the whole allowed to remain perfectly still for several days.
Meantime the planulae rising from the bottom, in the course of metamor-
phosis, are intercepted from the surface of the water by the watch-glass,
to which they will adhere. I have sometimes found them do so in two
days. After remaining there two or three days longer, the watch-glasses
should be removed to another vessel of water, and kept in an inclined po-
sition, the concavity where the planulas adhere being downwards. Many
young hydrae will be next seen, pendent by the prolonged apex, in the
course of eight days. It is preferable to have only a few in adhesion, in-

no ZOOPHYTES.

stead of a number, confusing the view. The subjects secured in this man-
ner are afterwards easily accessible.

I have attempted to feed these original hydrse with the expressed
juice or minute particles of animal matter : but I cannot affirm it to have
been attended with positive success. They are on the whole much more
perishable than the young generated by gemmation from the side of the
adult animal.

The preceding narrative proves that the parent of the Marine hydra,
under discussion, is a Medusa. No such parent has been hitherto as-
cribed to the hydrse of the fresh-waters, though the resemblance between
the two be so intimate: nor has any similar metamorphosis been conjectured.

Yet we ought not to relax our exertions to discover such a singular
natural process there, — nor, I will own, should I be much surprised were
something analogous found by the industrious explorers of the mysteries
of the Divine creation.

§ 3. Origin of the Medusa Bifida, the Cloven Medusa. —
Plates XVIII. XIX. XX.

We have viewed the subject of the first and second paragraphs of this
chapter exclusively as a hydra or polypus, an animal apparently perfect in
itself, and subsisting in independent life — presenting all the properties of
that singular genus ; nor exhibiting any such discrepancies as to sanction
its removal to be incorporated with some other race. It visibly originates,
feeds, breeds, lives, and dies, after the same manner as the rest of the
species ; therefore, in as far as we have gone, we should associate it with
them. A creature which survives for years, which transmits its form, to-
gether with all its peculiarities, to its immediate progeny, and to remote
descendants, seems at first sight entitled to a distinct position in the Sj/f:-
tema Natiirce.

But as no observation can be too correct, nor any reasoning unsus-
tained by direct evidence, too profound, so ought due precaution to warn
the naturalist against receiving presumptions for facts.

MEDUSA BIFIDA. Ill

We have still to look farther, — to dive deeper into the obscure sub-
ject before us.

From one notable peculiarity of the Hydra gdafinosa, Strobila, Tuhu,
or by whatever name it shall be recognised, our notice must be now di-
rected to an animal of altogether an opposite origin, one entirely different
in form, in habits, and in permanence, though between the two there be a
union or connection, hitherto insuflficiently understood.

The figure and the properties of this creature annex it to the Medu-
sarian tribes, whose history would admit of long and interesting commen-
tary, as seen from a few preceding observations.

Meantime, I shall consider the being alluded to, nearly as I have
viewed the former, that is, chiefly as a perfect and independent animal, or
an animal advancing towards perfection, until more versant in its history.
Herein there are various obscurities which I cannot pretend to explain.
Nevertheless, the curious and inquisitive, whose attention is attracted to
them, may be able to offer a satisfactory solution, through some connected
chain of facts, of what has appeared to me enigmatical.

I confine myself entirely to what I have seen.

Long ago, I had remarked colonies of minute transparent animals,
swimming in vessels of sea- water, during the months of February, JVIarch,
and April. Their general aspect very much resembled a flock of birds in
distant flight, as represented by landscape painters. — PI. XVIII. fig. 1 ;
PI. XX. fig. 1. After being transferred to vessels free of other subjects,
they continued several days in activity, and then disappeared. I could not
account either for their origin or their transience. They occurred only at
rare intervals, and always identically under the same form.

More accurate inspection on these occasions, and subsequently, showed
the alliance of such creatures to that comprehensive genus the Medma,
both in configuration and in habits. But the date of their appearance
did not correspond with the wonted periodical ascent or arrival of that
tribe to the surface of the Scotish seas during the summer months. In
the year 1826, I found them as early as the 6th of February.

The whole of this remarkable race is now partitioned into several di-
visions, founded on their common aspect or individual properties. But

112 ZOOPHYTES.

some of the most important characters are so equivocal, and some species
so difficult of attainment, that their proposed arrangement already requires
revisal. Nevertheless, the prominent features assumed prove useful for re-
cognition. Among these are the substance of the animals, gelatinous, con-
sistent, opaque, or transparent ; their spherical, ovoidal, or campanulate
form ; circumferential lobes, or fringes ; ciliated or simple tentacular pro-
cesses ; solid or hollow extensile and retractile appendages, — and alto-
gether exhibiting such varied configuration as precludes the descriptive
powers of language. Next are their delicate iridescent or deeply con-
trasted colours : their strange and peculiar motions, laboured, tardy, or ex-
peditious, suspension amidst the water, or traversing it in all directions, by
means of the fleshy oars which provident Nature has given them. Multi-
tudes quitting their dark and wintry abodes below, or voyaging, from distant
regions, come to embellish our Scotish seas, as if seeking to enjoy the
fine and tranquil temperature of summer.

The species to which I shall devote a brief discussion here, and that
only because it seems doubtful whether more skilful authors have pre-
served individual specimens under permanent observation, was not un-
known to earlier naturalists. By Baster it was denominated Medusa mi-
nutissima, and being in fact among the more minute, it may be rather con-
sidered a microscopic object than otherwise. Its expansion is between
one and two lines ; nor have I been sensible of its increment during the
longest period, that is sixty days, of its survivance.

This creature's body consists of a central disc, with from four to twelve
horizontal flattened cloven lobes or arms. An organ like an obtuse-sided
cluster column, projects from the middle of the under surface, correspond-
ing to the site of the proboscis of other Medusae, around the origin or
base of which are four peculiar organs. That is the number when the set
is complete, each consisting of two flexible members like fingers. The
general aspect of the Medusa, enlarged, is represented Plate XVIII.
figs. 2, 3, 7, 8 ; proboscidal organ a ; lobes b. The four organs around
its basis are seen figs. 4, 5. Also the general aspect of various subjects is
represented Plate XX. figs. 4, 5, 23, 24, 25, all enlarged.

Each lobe is cleft half way down. A cone in the centre, at the

MEDUSA BIFIDA. 113

bottom of the cleft, is surmounted by a black speck, which a powerful
magnifier exposes as a number of smaller specks on a lighter ground. This
somewhat resembles the structure of the specks terminating the rays of
the star-fish. Many consider the specks which are disposed at intervals
on the margin of large and of smaller Medusae as ocular, but it might be
well to investigate whether, both there and in the Asterise, they are not
rather of a glandular nature. — PI. XVIII. fig. 6, magnified lobe and cen-
tral cone. The whole surface of this minute Medusa is finely speckled or
granulated, which, as the other parts, can be clearly discovered only by
microscopic powers. — PI. XVIII. figs. 7, 8.

The animal moves by jerks or bounds, from collapse of the body and
percussion of the water by the lobes. As all other Medusae, it shews a con-
stant tendency to seek the surface by an oblique or perpendicular ascent.
Sometimes, but rarely, in reversing itself, the proboscis appears like a
crest above, fig. 3, which affords the most favourable view of the whole
formation ; and it generally drops gently down among the water, with the
proboscis below and the arms extended. Resting in equilibrio, the pro-
boscis is downwards, and the lobular arms slightly recurved, fig. 2.

This Medusa courts a moderate degree of light. Then it always rises
to the surface, an invariable characteristic of the Medusarian race, for it
seems adverse to their nature while in vigour to remain below. Weak-
ness and inaction are denoted by their permanence there. But the light
beinf bright the Medusae incline to shun its intensity ; though heat and
licht be the chief incentives to motion, not only among them, but of many
of the lower tribes.

For the most part, the existence of the cloven Medusa is very tran-
sient. It appears unexpectedly, and in a few days it decays or vanishes.
With the utmost precautions, I have never been able to protract its
life above 55 or 60 days from its origin. On its earliest escape to an
independent existence, it seems fully developed and endowed with
ample vigour. No sensible increment, accession, division, or reduction
of any portion ensues during the whole currency of the period here
specified, nor any change or alteration farther than that concomitant
on declining strength and activity. The size of the specimens repre-
VOL. I. ^

114 ZOOPHYTES.

sented Plate XX. figs. 5, 25, was then nearly equal, when 40 and
50 days old respectively. It is seldom, however, that any can be pre-
served so long. The whole individuals of a numerous colony perish suc-
cessively. Their motion relaxes ; it becomes feeble and laboured ; they
cease to ascend ; and remaining at the bottom, their lobular arms closing
over the disc, the whitened colour and globular shape show them like
seed-pearls, when they languish and die.

Sometimes, while still somewhat transparent, they disappear from

amidst the water.

Though occasionally recovered directly from the sea with other col-
lections, I was led to remark that they had been chiefly observed in vessels
containing the Hydra tuba or Sirolila of M. Sars, and that, when removed,
they were frequently replaced by others. But I could find no visible
spawn, fragments, or other elements, to which I could reasonably ascribe
their origin : nor were any Medusae ever to be seen bearing the most re-
mote resemblance to them.

Then and afterwards I found their greatest abundance in March ;
that they occur from the beginning of February, during 40 or 50 days ;
that they are not to be seen from that season, at least in captivity, through-
out the rest of the year, in Scotland.

Many of the rules and principles which determine the multiplication
of the highest orders, also extending to the lower tribes of animals, may
suggest some analogies here.

Eight of the Medusae being observed on February 6, in a vessel with
many specimens of the hydras which had been long under observation,
they were removed a day or two subsequently. I conjectured them to
have come in a replenishment of sea-water on the first of the month.
These were succeeded by others appearing in the same vessel on the 14th
and 15th. I had remarked a convulsive motion among the tentacula of a
Hydra on the evening of the 14th, apparently from a Medusa having been
entangled there. The like occurred next morning, when one was libe-
rated.

Similar convulsive motion agitating the same hydra during the 16th,
it was brought under closer inspection ; for, unable to discover the like
spasmodic demonstration among its companions, at least 100 in number, I

ME:DUSA bifida. 115

was surprised that, amidst such an host of enemies to all living creatures,
— those mercilessly devouring whatever they could master — the Medusa
should dwell with impunity, involved by the very organs of capture.

On dislodging the subject, apparently a hydra of medium size, with
scissors, and transferring it to a watch-glass, nothing but the wonted con-
vulsion, which proceeded from the clasping of the arms of a Medusa
upon the surface, disc, or extremity, was seen on the morning of the 17th.
However, several were swimming at large next day ; the size of the sub-
ject had diminished, and it was visibly indented by deep corrugations.

But now I found, and in good time for correction, that I had been
somewhat mistaken, as instead of a Medusa having been detached entire
by the sharp pointed scissors employed, I had severed only the corrugated
portion, along with a slice of the smooth fleshy basis sustaining it, as will
be better understood in the sequel. In fact, the position of the subject
precluded the free use of the instrument designed for insinuation of the
points below each side of the apex, so that the edges had been applied.

The vessel whence this subject was removed contained a colony ori-
ginally consisting of ten hydrae, which invested the empty shell of a Ser-
pula, as described in a preceding paragraph. There the colony dwelt, fed,
and bred by uninterrupted gemmation. Thus it was occasionally aug-
mented naturally, and reduced accidentally, until in three years and three
months not fewer than the number above mentioned, at least 100 of its
members remained.

No other animal had been introduced among them.

The hydra, as observed, in its proper site is suspended by the apex,
at some elevation, whence the body hangs down so as to afford free scope
for the exercise of the descending tentacula. Therefore colonies in con-
finement disperse on the sides of the glass as most congenial to their nature.
But the diminished proportions of the apex, which would be otherwise a
sustaining base, sometimes renders their position so insecure that they drop
from it.

Returning to the subject in the watch-glass, it resembled an inverted
conic ftustum of yellowish colour about three lines in length, proving then
and ultimately to be wholly composed of Medusae, in various stages, un-

116 ZOOPHYTES.

less the tliin slice below. Tlie arms clasping at the summit belonged to
the animal most mature. Many more in the lower part of this series soon
became active ; but in the portion still under them were absolute quies-
cence and indefinite forms. Seven advancing Medusa in all might be
enumerated in the mass, in the course of this day, the 18th of February.

The subject is accurately illustrated by a satisfactory representation,
Plate XVIII. fig. 13 ; enlarged, fig. 14 : Medusa most mature, a ; others
less mature, h ; slice of the fleshy basis, c.

The importance of this fragment, the slice, apparently so insignificant,
will be shown afterwards.

Next day, the 19th, at noon, a Medusa was observed to have quitted
the subject, necessarily the highest in the series, and hence at the upper
or larger part, and another swam at large in the evening. Further, a third
having escaped on the following evening, all these three were free.

Next day, that is, on February 21, after vehement clasping at the
summit of the mass, a fourth was liberated, while new struggles to escape
appeared in the place it had left ; and on the morning of the 22d, six in
all were swimming in the water from further liberation during the night.
A seventh, freed on the 23d, swam with the rest ; and these seven, pursuing
their course, or suspended in equilibrio, resembled as many minute
stars.

To ascertain more correctly what might follow, I thought it expedient
now to remove the whole, as they should have exhausted the number
whereof the severed conic frustum had apparently consisted on the 18th.
Still, the clasping of the arms of an eighth Medusa ensued, though not
liberated until next day, the 24th, at which time the inverted cone, or
series of animals, was much reduced from its earlier dimensions.

At this juncture there was reason to conjecture that the smooth slice,
or basis of the subject, figs. 13, 14, c, adhering slightly to the watch-glass,
was something different from the animals successively quitting their posi-
tion above it, and that it was truly either an entire hydra, or a portion of
one. Besides, a spur such as described in the preceding chapter had
issued from it two days previously.

A ninth Medusa, which had been clasping feebly for two days, also

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MEDUSA BIFIDA. 117

was liberated on the 26th ; and at the same date, a tenth likewise clasp-
ing, seemed nearly mature, while this last yet remained in its place,
fig. 15, a. An eleventh, only partially developed, fig. 15, b, appeared
rather towards one side, which could not be seen distinctly without the
microscope. Several tentacular organs, supposed to be those of the origi-
nal hydra, were now in view, when the subject with the two animals was
delineated on February 26.

But these two animals remained so long in the same position, that I
concluded some unnatural incorporation with the basis or sustaining sub-
stance, c, had certainly ensued, nor, that it might have been so, is difficult
to be understood, considering the constant evolution and ready adhesion of
living matter in such products. I daily expected their liberation, how-
ever, as the basis was firmly fixed, and extending on the watch-glass on
the 6th of March, and was still more evidently a hydra.

On the 10th of March, the clasping of the tenth was alone visible ;
the eleventh had disappeared ; and in a day or two its companion, the
tenth, disappeared also, without liberation, that I could discover.

Thus the daily progress of this subject, apparently a formation on the
disc of the suspended hydra, had been uninterruptedly followed from the
14th of February until the 12th of March, or nearly four weeks.

Ten or eleven days after separation by the sharp-pointed scissors from
the side of the vessel, while Medusse were coming to maturity, and escap-
ing from the one extremity of the subject, the probability of its basis, the
smooth fleshy slice, proving a hydra, was ratified by the partial protrusion
of tentacula. The fact was verified by its subsequent adhesion and diffu-
sion on the watch-glass ; nor could any doubt possibly remain when, on
the 25th of March, being entirely free of the Medusae, its long silky-look-
ing tentacula were waving in the water. Further, its nature was unequi-
vocally demonstrated by the germination of a young hydra from its body
a month later ; and in May, another descendant of one or other of the two
had established itself independently.

From this detail it is obvious, that the progress of the Medusae to ma-
turity is progressive, and that a considerable interval, perhaps a whole
month, may elapse between the liberation of the first and of the last.

118 ZOOPHYTES.

The preceding was among my earlier observations. Their extension
and confirmation were desirable ; especially from such subjects being rare
and unmanageable.

Long afterwards, I availed myself of the under valve of a large speci-
men of the Pecten Jacobmis, a kind of clam-shell, which bore about 150
of the Hydra tuba, when withdrawn from the sea on the 21st of March.
The external convexity was invested by the white Alcyonium digitatwn or
Lobular ia : and a portion of the concavity, occupied by tubes of the Tere-
bella, with and without their tenants. Having extirpated the former, and
the surface being carefully brushed perfectly clean of impurities, and the
latter, to which many hydrse were adhering, having been removed, I com-
puted that about 110 specimens remained, distributed over the inner sur-
face of the valve. The outside was quite free of them.

All were of very moderate dimensions, having probably dwelt in a
barren place, as animals of this kind enlarge so readily where subsistence
abounds. Some were sjTnmetrical and perfect, with an ordinary comple-
ment of long flowing tentacula.

But, at least one-half of this numerous colony was undergoing a re-
markable change ; and to an indifferent observer, the shell had no distant
resemblance to a surface overspread by above fifty grains of rice affixed by
one end.

Those thus distinguished were interspersed promiscuously amongst

the rest.

They exhibited various features. For the most part the hydrae de-
finitely affected consisted of a smooth bulbous base, root, or foundation
next the shell, surmounted by an indented or whirled cylinder, which was
crowned by a circle of sufficiently active tentacula. The peculiar position
of these hydrae denoted little distinction ; all were pendent according to the
nature of the tribe, some inclined and others curved slightly as they hung.

PI. XIX. fio-. 1, portion of the shell and subjects somewhat enlarged.

Figs. 2, 3, subjects nearly according to Nature : the latter as they ap-
peared a week later than in fig. 1, on March 29.

Many of these subjects were now environed by plain circles, as if
faintly indicating segments ; fig. 4, enlarged.

MEDUSA BIFIDA. 119

While in this state, such spontaneous influence is exerted over the
whole specimens, that the contraction of the cylinder shortens the interval
between the circles, or the whirls, if they be prominent, compressing
them on the bulb. As the cylinder relaxes, the intervals are wider, and
the whirls become more distinct; the subject is lengthened.

I call the formation a cylinder or roll, as in the earlier stages it ap-
proaches this figure ; and it very much resembles a minute rouleau of sil-
ver coinage. Other subjects, farther advanced, exhibit waved instead of
plain circles around the pillar, roll, or cylinder. — PI. XIX. fig. 5 ; XX.
fig. 2. Short clefts likewise indent the convexity of the waves, especially
towards the row of tentacula still subsisting at the summit b.

It must be observed that this row of tentacula, consisting of twenty
in some subjects, is remote from a, the smooth, simple, fleshy bulb.

The number of circles, whirls, or wavings of the cylinder are indefi-
nite. All are not formed at once, and by the result it has been computed
there were twelve, fourteen, twenty, or more ; as many as twenty-seven
seemed to belong to one specimen. The number augments : a plain whirl
next the bulb may be converted to a waving circle in a day or two, or less.
The advance towards change or maturity is always progressively upwards.
Thus the portion of the cylinder next the bulb may be deemed an elemen-
tary stage, and the farthest from it the most perfect subsisting stage.

Desirous of pursuing the history of individuals from earlier date to
the latest period, I detached several single specimens thus affected, by in-
sinuating the point of a stout pen-knife, so as to split off a fragment of the
shell, which was little larger than the base of each subject. This could
be attached by some adhesive composition to a watch-glass, and suspended
in a convenient position.

Several being obtained in this manner, all were isolated. They were
such as Plate XIX. figs. 4, 5 ; and Plate XX. fig. 2 ; the last two being
farther advanced than fig. 4, the first referred to.

The whole consisted of a plain adhering bulb, sustaining a prolonged
roll or cylinder, of which the extremity was crowned by a circular row of
tentacula.

These tentacula were not alike vigorous and active in all the subjects.

120 ZOOPHYTES.

In some they were shorter and less regular. Indeed, if we reflect on their
original office of seizing or conveying food to the mouth, their functions
are now no longer necessary. Apparently the base of the pillar rests on
the wonted site of the mouth of the hydra.

But in the next place, before the progress of the subjects composing
the roll is very far advanced, the circular row of tentacula at its extremity
disappears. It is entirely obliterated. — PI. XIX. fig. 6. Now a new row
is discovered, — sometimes emerging as simple stumps or protuberances, —
from the circumference of the fleshy bulb whereon the root or base of the
pillar is implanted, therefore, not in the vicinity of the first or terminal
row. They are removed by a considerable interval. — PI. XIX. fig. 6, a ;
fig. 7, a. PI. XX. fig. 3, a, c ; fig. 15, a, c. Their growth is more or less
rapid. Sensible elongation ensues in 24 hours.

Meantime the cylinder is extended, the wavings seen on its surface
next opening, like basket-work, allow the transmission of light through
their interstices; the cylindrical form gradually alters, and the whole
figure becomes an inverted conic frustum, enlarging outwards. The bulb
also is refining into the shape of a hydra, on the disc of which the summit
of the frustum is implanted. — PI. XIX. fig. 8. The same, 24 hours later,
is represented fig 9. The subject seems divided into several different
strata, or if considered a rouleau, of several distinct coins.

As the subject apppoaches this stage, a convulsive motion is visible
near the extremity, b, figs. 8, 9, comprehending three strata, perhaps, while
below and nearer the new circle of tentacula, c, all is tranquil and quies-
cent. As the waves have been moulded into cloven lobes, this convulsive
motion is occasioned by their clasping inwards, towards the central projec-
tion, h, d, fig. 9. Some animal evidently struggles for liberation, which,
by vehement and incessant exertion, as said before, at length succeeds, and
it swims at large as the Medusa. — PI. XVIII. fig. 1 ; XX. fig. 1.

Such in abstract was the course of alteration of the subjects investing
the shell of the Pecten ; interspersed with which were numerous perfect
and symmetrical hydrse.

First, a smooth fleshy bulb sustained a cylinder of about half its own
diameter, indented by plain circles, which were soon converted to waving

MEDUSA BIFIDA. 121

curvatures. A row of 20 or 24 tentacula crowned the summit of the
cylinder, which row disappeared or was obliterated as the waving in its
vicinity deepened, and the diameter of the cylinder there expanded, that
is towards the summit. Concomitant on obliteration of the terminal row,
a new circle of tentacula, at first few, but gradually augmenting, was emerg-
ing from around the bulb, while the struggles of Meduste, into which the
waving strata were evolving, accomplished their liberation to swim uncon-
strained in the surrounding element.

Before I speak of the period required for this evolution, together
with some incidental observations, I shall advert briefly to some facts of
early occurrence.

I was then impressed with the belief of the original tentacula of the
hydra undergoing a change, being obliterated by a foreign substance im-
posed or generated on the disc, and that, as this substance, in fact com-
posing the roll, pillar, or cylinder, was dissipated, the tentacula resumed
their extension. Certain circumstances seemed to sanction my opinion.

In the course of a long series of observations with which I was then
engaged, a single hydra having fallen from its place, it was transferred to
a separate vessel, wherein two years afterwards, its descendants were found
amounting to 45. Of these 42, along with itself, occupied the sides of the
vessel, and the remainder were afiixed to the bottom. With greater care,
perhaps, their numbers would have been augmented.

In two years and eight months from commencement of the observa-
tions, one in the new vessel, which I conjectured the common progenitor
or parent hydra of this colony, dropped from its position on March 5. I
wish to specify dates as a guide to the period when naturalists may expect
a solution of their enquiries.

Next day the figure of this subject seemed elongating, and in three
weeks the wonted pendulous roll appeared, as it lay in a watch-glass, as
in Plate XVIII. fig. 9 ; enlarged, fig. 10.

Nothing but the colony of hydrse had occupied the vessel.

The animal had fallen on March 5 ; it was delineated on March 25.
In five days the cylinder equalled about two-thirds of the length of the
whole subject, the remainder being smooth. It was about a third of the

VOL. I. Q

122 ZOOPHYTES.

thickness of the smooth part, which I considered the original body of the
hydra, now towards a line in diameter. But it must be recollected all
these measurements and proportions are to be deemed only approxima-
tions to the truth.

Recently, preceding March 30, two of the largest companions of
figs. 9, 10, — still suspended by adhesion to the side of the same vessel, —
were undergoing a change, the tentacula were shortening. The body re-
mained plump and healthy, when only the tips of the tentacula continued
visible at the extremity of the pendulous prolongation. — Plate XVIII.
tig. 11, h. This subject extended five-eighths of an inch. The pendulous
prolongation of its fellow, fig. 12, whose tentacula had entirely disap-
peared, was still more ample on the 30th of March. Its total length was
about five lines.

In a week, that is on April 8, numerous other specimens in the for-
mer vessel which had contained figs. 13, 14, were undergoing changes
similar to those now described.

Suffice it to observe, in this place, that the pendulous rolls were gra-
dually advancing to maturity, and progressively resolving into Medusae as
the former.

It is to be remarked of the four animals whose history is thus abbre-
viate, Plate XVIII. figs. 9, 10 : 11, 12 ; 13, 14, 15, no other creatures
had been in the same vessels along with them ; nor could the strangers
have escaped detection if there, — the vessels being only two inches in dia-
meter. From the numbers in one of them, the hydrse were of all ages.
Although I have endeavoured to describe and represent the actual
appearance of the subjects, and to follow the course of incidents as accu-
rately as possible, there are still various points which I feel sensible of
having overlooked, and others which there was no opportunity of observ-
ing, both meriting much farther investigation.

Certain facts admit of no dispute. Such as the existence of a vigorous
hydra attached to a solid substance, with long flowing silky tentacula : an
alteration in the figure'^of the body, or the formation of an embryonic roll
of Medusaj on the disc ; the gradual maturity of each Medusa, and its
liberation from the roll ; the disappearance of the original tentacula of the

MEDUSA BIFIDA. 123

hydra : the emerging of a new circle of tentacula from a smooth fleshy
bulb, sustaining the embryonic roll, as the former are obliterated, and
as the Medusse approach maturity, the evolution of this fleshy bulb as
a perfect hydra, along with their departure, which becomes the parent of
progeny by gemmation, and its permanence as an independent animal.

Among the various questions to which the attention of naturalists
should be directed, is —

1. How is the body of the hydra afifected in the earliest stages of al-
teration ? I rather thought that it was by progress downwards, the first ap-
pearance of change taking place near the circle of the original tentacula.

2. Is it truly an alteration of the body itself, or is the change from
the embryonic roll being originally generated within the body, or upon the
disc? I found it impossible to determine, until ascertaining this fact,
whether the subsequent division and dissolution was that of the hydra itself,
or of the product generated from it or upon it. I rather thought, when
the most favourable view could be obtained, that the smaller end of the
roll, when the rest had advanced, appeared as if inserted in the hydra's
mouth, or where we should expect to find its mouth.

3. How and when is the original circle of tentacula obliterated ? It
appeared to me, that, as the waving of the cylinder deepened, the vigour
and regularity of the circle I have described as consisting of 20 or 24 ten-
tacula, were impaired ; that they contracted and were effaced. I could
not discover how, if they belonged to the fleshy bulb, they were conducted
around the expanding Medusan lobes to the extremity. Had it been so,
their obliteration might have followed simple contraction, and possibly
they might have extended as new tentacula, for the hydra has uncommon
power over its parts.

The terminating circle seems somewhat within the circle of maturing
MedusEe. That is, the Medusan circle is of larger diameter than the ten-
tacular circle.

This latter circle seems quite unconnected with and distinct from the
hiffhest Medusa, whose liberation, in as far as I could discover, never pre-
ceded obliteration of the tentacula. I have witnessed this incident, but
the first Medusa escaping before me, was always free of foreign organs.

124 ZOOPHYTES.

I have also seen several of the first Medusse, both before and after libera-
tion, and all alike free. '

To these and other points I shall venture to direct the general atten-
tion of naturalists. Scotish observers will find the proper season of their
enquiries regarding the hydra indefinite, but regarding the Medusae they
are restricted from about the first of February until the first of May. No
Medusse were produced from the hydrse in my possession, after the 15th
of April in the year 1846.

But the subjects are so diminutive and so perishable ; of such rare
and uncertain occurrence, as to preclude any premeditated course of obser-
vations ; or the expectation that a series interrupted may be resumed and
completed fi-om new specimens, at any given time. Hence a perfect his-
tory of them would require the united labour of many observers for many
seasons, aided even by fortuitous and advantageous incidents.

Little remains for addition to this already too prolix detail. It has
become so from an anxiety to render an obscure and difl5cult subject in-
telligible by those who may not have the benefit of practical experience.

All the Medusse in the embryonic roll are separate and distinct ani-
mals. Each is in close application to that which is next below, if itself
be uppermost ; or lays between two if intermediate. The proboscis is
outermost if the individual be uppermost in the roll ; thus all lie in the
same direction, the proboscis outermost, as the Medusa escapes, from the
next left behind. When the last remains in adhesion to the fleshy bulb,
its proboscis projects outwards also. Thus the under surface of the em-
bryo is always outwards, while a portion of the roll.

This is a singular arrangement : it shews that Nature designs that the
maturity of the embryos, and their liberation into active life, should be
successive. Whether the brood be confined within some invisible amnios,
collectively or individually, in an earlier or later stage, is uncertain.

The period occupied by the change, and that which is consumed in
the dissolution of an entire roll, is extremely variable. It usually takes
several days. But I have seen a single Medusa free itself within three
minutes after its precursor departed. The higher two of Plate XX.
fig. 16, separated during observation. The four higher of Plate XIX.

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MEDUSA BIFIDA. 125

fig. 8, having become more amply developed, as in fig. 9, were under such
vehement exertion at noon, soon after obliteration of the tentacula, that
I felt impatient for the arrival of my artist to delineate the whole subject
■while yet entire, which he accomplished. — Fig. 9. Accordingly, two to-
gether were liberated just as the drawing was completed. After struggling
severely, they were free of each other. Many days sometimes elapse
before dissolution of the roll as previously observed.

When a drawing of Plate XX. figs. 6, 7, was begun, the lower part
of the roll was merely a smooth swelling whirl ; but previous to comple-
tion of that and another, the conversion of the whirl to an early embryonic
Medusa was perceptible. In nine days the whole Medusas of this subject,
fig. 7, were liberated, leaving the hydra free.

The period is irregular, as may be readily supposed from the unequal
numbers composing the roll. I could not ascertain that above seven
strata ever came to perfection in Plate XX. fig. 15. But in others they
exceed twenty. ,

In proportion to the Medusae liberated from the expanding conic
frustum its dimensions are gradually reduced ; but the symmetry of the
sustaining bulb is improving, and its tentacula are extending. Their pro-
gress is alike variable ; also certain parts are generated, which afterwards
disappear.

Several Medusae having escaped from Plate XX. fig. 8, only three or
four remained on March 31, the bulb now becoming a hydra with extended
tentacula. In five more days the hydra was symmetrical, with a long spur
issuing from the side, fig. 9, which disappeared subsequently. In other
three weeks, a young hydra had been generated, and on May 16 it was
nearly as large as the parent, a, from which it had withdrawn, fig. 10.
Fleshy portions, such as fig. 11, enlarged, promised embryos, but they dis-
appeared. The hydra of this subject, figs. 9, 10, a, survived 125 days
after being freed of the Medusa. It had also generated several young ;
but having gorged itself with food, it was lost accidentally.

If the period occupied by the changes is irregular in point of dura-
tion, the ultimate issue is definite. For example, the tentacula crowning
a waved roll or cylinder implanted on a simple bulb, Plate XX. fig. 2,

126 ZOOPHYTES.

were obliterated in two days, as seen by fig. 3. Tlien a different row of
tentacula was advancing from the higher circumference or disc of the bulb,
and four spurs afterwards disappearing were issuing from the base. Now,
a hydra was forming of the bulb, whose long silky tentacula were waving
in 25 days amidst the water, fig. 12. After other three weeks, the indi-
cations of progeny, shown fig. 13, were realized by the representation,
fig. 14, of the perfect hydra with its offspring, as seen 53 days subsequent
to the delineation of fig. 2. The progress of this subject was somewhat
retarded by an accident. But in 121 days from that delineation, fig. 2,
it had become fine, when its vessel was unluckily broke during the night,
and the contents lost.

The changes and the multiplication of others proved alike evident
and decisive. Thus the subject, Plate XX. fig. 15, so prominently distin-
guished there, after passing through the changes of 16, 17, and 18, became
with its progeny as represented fig. 19, in 48 days. Following its course,
first, it is seen as an enlarging waved rouleau, with a circle of above 20
tentacula at the extremity. This roll is sustained by a bulb with a circu-
lar row of shorter tentacula, d. An embryo, e, is germinating from the
bulb. In a week, the farther or exterior row of longer tentacula has
disappeared, and the inner or shorter row is extending, fig. 16, c. In an-
other week, all the Medusae composing the rouleau have escaped ; the
hydra, originally a smooth fleshy bulb, and its germinating progeny were
advancing, fig. 17. The changes were great with the lapse of 15 days
more. Now the progeny amounted to four, one of the number, a bud with
developing tentacula ; other two have withdrawn ; the fourth, very minute,
has sprung of some of the family, fig. 18. In 48 days the whole appear
as in fig. 19. The parent became ultimately the finest of all the hydrae
which had been simple bulbs sustaining Medusae. It fed voraciously, and
about three months after the whole Medusae had been liberated it gorged
itself to such excess, that the adhesion was lost, as I presume, from dis-
tension ; thence it fell down and perished.

Amidst numerous examples which I have had an opportunity of wit-
nessing, I shall give only one additional illustration corroborative of the
general facts.

MEDUSA BIFIDA. 127

A vigorous subject attached to a fragment of shell on March 27 is
represented, Plate XX. fig. 6 ; enlarged, fig. 7. The different strata of
Medusae are advancing rapidly to maturity : the bulb has attained the ge-
neral form of a hydra ; and its tentacula are extending with some regu-
larity. Though pendulous originally, the Medusan roll has assumed a pe-
culiar curvature, so that the most mature portion turns upwards. In 28
days longer, nothing of this subject but a vigorous and symmetrical hydra
remained, fig. 20, which in 15 more, had become the parent of others,
fig, 21 ; and in two months from the beginning, in March, its family had
increased to seven members, fig. 22. This parent, originally a bulb on
March 21, fed readily and copiously, and survived in fine condition 290
days from that date.

Thus it is unquestionable that, wherever there is a roll of Medusae there
is also present a hydra sustaining it, which is developed in symmetry as
the Medusae escape.

How this hydra comes to be present is a difficult question. Is it an
original hydra, whereof the tentacula are obliterated, and the body com-
pressed ? Has the roll been generated by that hydra, or is it a foreign
substance ? Is the body of the original hydra actually partitioned into a
number of Medusa, all except a portion at the base, developing as a new
hydra ? If any of these facts be admitted, it would be well to see its con-
firmation. My original impression was, that the body of the original
hydra still subsisted ; that it was disfigured, compressed, the tentacula ob-
scured, but that it recovered its shape. It is positive that, unless the bulb
be a new generation affixed to the end of the Medusan roll, that the whole
body of the hydra is not consumed and exhausted by the successive libe-
ration of the Medusae, for a portion becoming a symmetrical hydra is uni-
formly displayed from the point whereon the roll was generated, imposed,
or rested.

It is unnecessary to recur to the history of the Medusa. Sometimes
an unnatural adhesion of two or more takes place in the embryonic roll,
from which they should be detached singly, in the regular course of its
dissolution ; and there are sometimes real monstrosities, as repeatedly oc-
curring among the lower tribes.

128 ZOOPHYTES.

Thus, more than two in adhesion, Plate XVIII. figs. 16, 17, fell
from fig. 12. On another occasion two united, showing no disparity in
the number of arms separated from a different roll.

A monstrous Medusa consisted of two bodies united by a fleshy neck,
the one body with four, the other with ten arms. — Plate XX, fig. 24.

Are the four sets of flexible organs on the under surface rudimentary
appendages ? — PI. XVIII. figs. 4, 5.

Although by repeated, long, and painful observation, I have endea-
voured to learn the history of the Hydra tuba, and the McdmcB originating
from it, my purpose has been but partially attained. I have selected many
individuals, and I have chosen colonies of both to discover whatever changes
they should undergo. The hydra grew, it fed, it bred, its existence was
long. The Medusa lived, it neither fed nor bred, its existence was infi-
nitely shorter ; nor did it undergo the smallest change from the first mo-
ment of liberation for 55 days. Its life could not be protracted, on any
occasion, beyond 60 days.

Between the form and habits of these two animals there is not the
smallest correspondence.

At the commencement of my observations many years ago, I was not
aware, as already said, of the Medusa having been seen by Bastcr, previous
to the year 1765, and distinguished by him as Medusa minutissima .
Therefore I named it Medusa bifida provisionally, from the cloven lobe.

Names already given, if significant, should not be capriciously
changed ; and as nothing but the pursuit of tmth ought to be the object
of literature, so should naturalists always contemplate that laudable end,
by endeavouring to penetrate the works of the great Creator, instead of
engaging in controversies — an idle occupation at best.

My special purpose is now to explain the mode whereby hydraoidal
zoophytes multiply their ofiBpring, or enlarge their dimensions, as deduced
from examples of the Hydra tuba ; and if the student follows its progress,
he will find the subject more easily understood.

The following conclusions, among others, may be deduced on the na-
ture and the relations of the Hydra tuba and the Medusa bifida : —

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MEDUSA BIFIDA. 129

I. The Hydra tuba is a real marine polypus, as distinguished by the
identical properties characterizing the two species, viridis siaiftisca, dwell-
ing in the fresh waters of Scotland.

II. It feeds after the same manner : its offspring are generated after
the same manner, by a bud from the side of the parent, which offspring
matures, establishes itself independently, and demonstrates precisely the
same nature.

III. Both these marine and fresh-water hydrae are apparently perfect
animals : they undergo no metamorphosis from the moment the bud is
evolved into form ; and they survive during years.

IV. Their nature corresponds in the tenacity of life : they enjoy to
the utmost extent the property of recovering mutilated parts.

V. At an indefinite period, and under indefinite circumstances, a
pendulous roll or column is observed, as if implanted on the disc of some
of a colony of the Hydra tuba.

VI. The pendulous column is a roll of embryo Medusae, resting in its
earlier stage upon, or attached to, a smooth fleshy bulb.

VII. It is faintly indented by circles, and is terminated by a circular
row of tentacula.

VIII. The indenting circles become deeply waved, the tentacular or-
gans at the summit of the roll are obliterated.

IX. The circumferential waving indicates the evolution of Medusae,
which are farthest advanced towards the summit. From their enlargement
the roll becomes a conic frustum, sustained by the fleshy bulb.

X. The Medusae successively attain maturity : they struggle vehe-
mently towards the extremity of the roll for liberation. A new circle of
tentacular organs, prominent before disappearance of the old circle, and
distant from it, is now evolving from the bulb.

XI. The Medusa? are successively liberated, and by their maturity
and liberation the embryonic roll is dissolved.

XII. The season of their generation, production, and liberation, is
limited by about 60 days, wherein the month of March is comprehended.

XIII. The period of their survivance, when free, does not exceed
60 days in confinement.

VOL. I. B

130 ZOOPHYTES.

XIV. The fleshy bulb refines into a perfect symmetrical hydra, as
the embryonic roll which it sustained is dissipated, and successive genera-
tions of progeny descend by gemmation from its side.

Plate XVIII. Medusa bifida.

Fig. 1. Colony of Medusae swimming at large.

2. Specimen enlarged ; supposed proboscis from the under

surface, a ; cloven lobes or arms, h.

3. Specimen reversed ; orifice of the mouth, a ; arms, h.

4. Surface, shewing four external organs around the pro-

boscis.

5. Another view of these organs.

6. Lobe or arm, shewing the cone in the cleft, surmounted

by a compound black speck, magnified.

7. Granulated aspect of the under surface of a specimen.

8. Granulated aspect of the upper surface.

9. Hydra, a, with a rouleau or pendulous formation, h, seen as

laying in a watch-glass, having fallen from its position.

10. The same enlarged, hydra, a ; pendulous formation, b,

being immature Medusae.

11. Hydra pendent from the side of a jar, a, with a similar

pendulous flexible formation, b ; consisting of imma-
ture Medusae.

1 2. Another hydra, a, become shapeless hke the two pre-

ceding, with a similar formation, pendulous from the
disc, b.

13. The pendulous formation with Medusae developing, a, b ;

detached along with a slice of the base or disc, c, as
now laying in a watch-glass.

14. The same enlarged.

15. Ultimate appearance of the same subject ; tenth Me-

dusa, a, struggling for liberation ; eleventh, b, died ;
spurs or originating tentacula, d ; the latter long and
silky in three weeks.

16. Portion separating naturally or accidentally from fig. 12,

proving two or more Medusae united.

17. The same, enlarged ; proboscis, a ; arms, b.

The figures 1, 9, 12, 16, nearly of the natural size : the
rest enlarged.

MEDUSA BIFIDA. 131

Plate XIX. Hydra tuba, Medusa bifida.

Fig. 1. Group of hydrse in progressive change adhering to a shell,
enlarged.

2. Natural size and aspect of a different portion.

3. Aspect of another portion, little exceeding the natural size.

4. Hydra and rouleau, or cylindrical prolongation, with circular

indenting, enlarged ; bulb, a ; tentacula, b.

5. Subject farther advanced, the tentacula at the extremity

subsisting, but the indenting waved.

6. Subject still farther advanced : tentacula at the extremity

obliterated. Another row originating from the bulb.

7. The same, as seen 48 hours later.

8. Bulb, a, with a spur' at the base, and the cylinder from the

disc, which is surrounded by tentacula.

9. The same farther advanced ; tentacula extending ; Medusa

greatly expanded ; the lobes clasping towards the pro-
boscis, d, which projects outwards.

10. Specimen with Medusse far advanced. Stumps on the bulb

subsequently extending as tentacula.

11. Subject natural size, consisting of a hydra with extend-

ing tentacula, sustaining several Medusse far advanced.

12. The same enlarged.

All the preceding figures, except 2. and 11, are enlarged.

Plate XX. Hydra tuba, Medusa bifida.

Fig. 1. Group of Medusse swimming at large ; natural size.

2. Bulb, or developing hydra, sustaining a waved roU of early

Medusse, terminated by a complete coronet of tentacula.

3. The same, having lost the coronet ; another distant coronet,

or circle, developing from the bulb, which is refining into
the form of a hydra, with four spurs issuing from the vici-
nity of the base : all as seen 48 hours after fig. 2.

4. Medusa as swimming at large.

5. Medusa 40 days old.

6. Bulb refining into a hydra, with tentacula sustaining a re-

curved column of Medusse attaining maturity ; natural
size.

132 ZOOPHYTES.

Plate XX. Fig. 7. The same enlarged.

8. Bulb become a hydra, with extending tentacula, from which

all the Medusae composing the embryonic column, but
three or four, had been liberated.

9. The same a week later, developed into nearly a perfect

hydra, all the Medusae being liberated ; a spur, c, from the
side.

10. The same in 46 days from the appearance of fig. 8. A

young hydra, h, having been generated from fig. 9, a, now
appearing as 5, in this fig. 10.

11. Vegetation proving unproductive from the base of fig. 10, a,

enlarged.

12. The subject a, figs. 2, 3, now become a perfect hydra ; natural

size.

13. The same with indications of gemmation.

14. The same five days later, a ; with its offspring, h.

15. A specimen undergoing progressive change. Bulb, a; co-

lumn of Medusae advancing, c ; crowned by a circle of ten-
tacula, h ; another circle, d, developing from the bulb.
Embryo budding, e.

16. The same a week later. The former coronet, 5, of fig. 15,

obliterated ; Medusae come to maturity ; tentacula from
the bulb advancing, c ; embryo, e, of fig. 15, having ac-
quired tentacula.

17. The same a week later, now free of Medusae ; embryo im-

proved ; gemmation indicated from the parent hydra, a.

18. The same in three weeks ; embryo budding, and young hydra

having withdrawn from the parent.

19. The same as seen 48 days subsequent to the appearance of

fig. 15, the family consisting of five independent indivi-
duals.

20. The subject, (figs. 11,12,) 28 days later, now consisting of a

symmetrical hydra.

21. The same in a fortnight, with its progeny.

22. The same 57 days later than figs. 11, 12, now a family of

seven independent individuals. These are somewhat con-
centrated in the drawing, being much dispersed on a watch-
glass.

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MEDUSA BIFIDA. 133

Plate XX. Fig. 23. Medusa with four lobes or arms.

24. Monstrous Medusa.

25. Medusa 50 days old, not having undergone any metamor-

phosis.
Natural size, figs. 1, 6 : 10-14 : 1&-22.

Plate XXI.

Fig. 1. Vorticella, enlarged.

2. Extremity of a branch of the same, magnified.

3. Vorticella of another species, enlarged.

4. Vorticella stmtoria ; group.
0. Part of the group magnified.

134 ZOOPHYTES.

CHAPTER IV.

THE SERTULARIA.

The preceeding observations on some of the Zoophytes already shew
the very comprehensive signification of their name, as applicable to a large
proportion of the animal creation. Within its sphere are included, soli-
tary, simple, naked, and unprotected creatures : it also embraces social,
complex, and well-sheltered beings, whether of pure organic formation or
combined, as we shall see, with inorganic matter of opposite elements.

On quitting the fistulous Tubularia, where the delicate hydra, con-
tinually exposed to danger, is denied a receptacle for protection, we reach
another race, the Sertularia, where it has always a safe retreat, within
something whose substance may be compared to membranaceous texture.
Again, leaving the Sertularia, we come to other tribes, for which Nature
has furnished a strong calcareous dwelling.

We shall find, however, in the progress of our enquiries, that the con-
figuration of the tenant sometimes undergoes a remarkable change, ac-
cording to the substance of the inorganic portion allotted for its habita-
tion.

The intimate resemblance of the hydra, I should say the identity of
that animal, combined with inorganic parts so different that we might be
scrupulous of allowing them a kindred place, is very strange. At first
sight there seems no common resemblance between two of the hydraoidal
Zoophytes, they are so far asunder. Neither is this less singular in the
Ascidian genera, where, of two which are beautifully displayed, we observe
the abode of one amidst a gelatinous mass, the other amidst a membrane,
and a third, perhaps, retreating within a shell — all originating with them-
selves, and augmenting as they are enlarged.

SERTULARIA. 135

The multitude of zoophytes having greatly increased, especially of
later years, with the number of observers, has demanded its partition into
lesser sections for convenience. But I am not aware that as yet the ad-
vances of knowledge actually admits the various divisions and subdivisions
proposed by modern naturalists. I fear we are premature in receiving
some of them ; for, allowing both their zeal and their intelligence, as ob-
servers, it seems to me, — I speak it with deference, — that we are still too
deficient in facts and in Jigtires, those radical elements, whereon alone un-
erring systems can be founded.

A strong propensity for the alteration of established nomenclature,
attended by an undue anxiety for the constitution of additional genera, has
recently predominated. Hence, precipitate observation has assumed tri-
vial distinctions as important characters, to support the addition or the
change, instead of permitting the favoured subject to merge among its
fellow species of some well-known and well-marked genus.

Probably the multiplication of genera will prove less expedient than
the enrolment of species. It can be scarcely doubted that, with the pro-
gress of more profound learning and investigation, so many analogies will
be found as to consolidate a number of species into a separate genus, or
to unite them to one already established : Also, that by the same means,
certain genera now admitted would be reduced to species. The constitution
of genera should repose on strong and indelible features, easily recognised.
It should be framed on species bearing some prominent reciprocal qua-
lities of form or of habits. But to found on the shape, the number and
position of the hairs, bristles, pencils, scales, warts, and the like, newly re-
vealed by every higher microscopical power, especially in the observation
of minuter animals, would almost require, for the reception of each, some
additional genus.

Perhaps as many animals, particidarly of the smaller tribes, remain
for discovery as those already known.

But I have never seen two animals exactly alike, however slight the
difference. On very minute comparison of two species, unless the ob-
server's views be proportionally enlarged, he will often question whether
each does not pertain to another genus.

136 ZOOPHYTES.

Common features must regulate the constitution of genera ; and the
profound naturalist, when completely master of the form and the facts,
will select such as are sufficiently prominent to sanction the arrangement
of a Sijstema Naturee.

In aid of this desirable object, I have endeavoured to point out some
peculiarities in the living products already discussed, as seemed more in-
teresting, and the least liable to be mistaken. I shall still continue a
similar course ; — yet, without affirming that, spite of all the care bestowed
on them, various essential characters have not been overlooked, or that I
have not erred in respect to some which should be corrected.

There is no doubt that sufficient distinctions subsist among the ani-
mated tribes, to warrant the association of few or of many in certain sec-
tions, and thus to facilitate the prosecution of science.

It is from the conviction of some principles being hastily and inap-
propriately adopted, that the names deduced from them are not more ap-
plied throughout these pages. Also, I consider it, meantime, better to
retain names already recognised, though not strictly appropriate, than to
disturb their application by interference.

If we confine the Scotish Tuhularice to zoophytes, " with a fistulous
stem, bearing a hydra which has two separate rows of tentacula, and ova-
rian clusters interposed between them," positive features of easy recogni-
tion define the genus, wherein the species comprehended are very few.

Were the name of Sertularia retained in its original sense, " a plantula
or little plant," — merely a diminutive, it would comprehend the great ma-
jority of those denominated flexible zoophytes.

I feel disposed to claim it occasionally as a useful and convenient
auxiliary, for which no adequate substitute has been hitherto suggested.
Our progenitors preferred brief and explicit definitions from clear and de-
cisive features. They did not deal in many words.

Nothing can be more appropriate for common use than the definition
in question, as in the Sy sterna — " an animal growing in the form of a plant :
Stem branched, producing polyjn from cup-shaped denticles or minute
cells." Further, the genus was divided into two portions ; one with a
horny stem, and fiirnished with ovarian vesicles ; the other having a a-us-

SERTULARIA. 137

taceous stem, tending to lapidescence, with rows of cells but without ova-
rian vesicles.

Endeavouring to reform the Systema, later naturalists have greatly
restricted the genus Sertularia, by mutilating it of many important mem-
bers. Of these they have constituted various new genera, not always suc-
cessfully, and sometimes under rather capricious denominations, as well as
founded on characters too vague and indefinite. Likewise the living sub-
jects having been seldom studied, or even beheld in them, while the skele-
ton was not rare, has perhaps led more readily to the assumption of re-
cently dead, and especially of dried specimens, as a guide for systematic
aiTangement.

Thus the inorganic parts are the basis of definition, — in the structure
of the stem, distribution of the branches, the shape, position, and number
of the cells ; while the figure and the properties of their fugitive tenants
remain totally unknown. Such must have been the obvious consequence
of the method pursued. Many may have found it difficult to do otherwise.

A modem author, however, Dr George Johnston, in a comprehensive
and excellent work on the subject, has gone far to rectify this defect, by
arranging the zoophytes with due attention to the nature of the animals
belonging to them. That author is entitled to the greater merit from the
labour and diflficulty of accomplishing such a task, for it has exacted equal
skill and industry.

Naturalists attempting to extend and improve the general Systema,
have been often unjustly and harshly blamed for apparent confusion and
defective precision, — faults not their own, but originating with those
writers whose works they were compelled to follow for want of better.
Had figures always accompanied descriptions, how much would it not have
promoted truth — ^how many complaints, and what grievous annoyances
would it not have prevented

Having disposed of the Tubularia, and by some examples deduced
from the nature of the hydra, having spoke of the process of increment,
whereby zoophytes are enlarged, we shall resume an examination of seve-
ral other subjects. But, always recollecting that as these are only a col-
VOL. I. s

138 ZOOPHYTES.

lection of detached memoirs, it is with less anxiety about their position in
systematic order than in the accurate detail of facts.

Unless in the stationary place of the head or hydra, while subsisting,
the double row of tentacular organs, and the pendent ovarian clusters in-
terposed between them, few positive distinctions will be found between
the general nature of the Tubularia and the Sertularia. A fistulous stem,
together with reproduction of the hydra, are not excluded from the latter.
But the metamorphosis accompanying the propagation of the Sertularia is
an important feature. Nevertheless, were the Tubularia ramea allowed
to remain in the position that naturalists now assign it, the correspondence
would prove still more intimate in a stem of aggregate tubuli and ovarian
vesicles, bearing within them the elements of new generations.

The extremities of the preceding Tubularise are simply cylindrical ;
but, excepting in the last, the Tubularia ramosa, without a tubular cavity
wherein the hydra can be withdrawn. The hydra which has rose within
the stem to develope from its extremity, remains permanently there. But
the extremities of the Sertularia are cellular, and a multitude of cells
are implanted on the stem, boughs, and branches, whither the hydra can
retreat for shelter, — all of various configuration. Some are little more
than a simple orifice : some resemble a tooth, a cup, a flask, or a bell, with
a smooth or a serrated lip. Some are armed with a longer or a shorter
spine : or the margin of others is guarded by several extraordinary pro-
cesses, extending in straight lines or in curvatures of inordinate length.
The cells, with their tenants, stand on one or both sides, or around the in-
organic parts : they are single, at distant intervals, in pairs, or in clusters,
either crowded together or far apart : And they are seated on stalks, or
branches, or twigs, jointed, whorled, or frilled. Remarkable profusion,
along with the greatest variety, are exhibited throughout the principal and
subordinate parts of the difierent genera and species constituting these
products in perfection, which nothing but a copious series of accurate de-
lineations from luxuriant specimens could illustrate.

Sertularise are beheld in every stage, advancing from meagreness to
the highest luxuriance. That specimen which has an hundred or a thou-
sand different hydrse, has an hundred or a thousand different receptacles to

SERTULARIA. 139

shelter them. There are neither too many nor too few. The dwelling
of each is coeval with the other,— originating jointly, but not invari-
ably corresponding in duration ; though in the hydraoid Sertularia, it is
not, as many believe, a portion of the living tenant's substance. The cell
serves as its proper habitation during life, and sometimes subsists perma-
nently or temporarily afterwards. It is a place of refuge, always in ready
preparation, whither the animal can retire for safety, or to undergo such
organic changes as are incident to its nature ; and from whence it can ad-
vance in quest of food, or to enjoy the salubrity imparted by its reno-
vated element. The vigour and the disposition of the tenant are sensibly
modified by these provisions for security. Unlike the inactive langour of
hydrse, deprived of such receptacles, here it is quick and lively, — as if con-
scious of danger, it lurks below : it is cautious of advance, and precipitate
in retreat. While completely unfolded, the whole organs suddenly col-
lapse, it sinks within the cell in a moment, and crouching still lower and
lower, lies quiescent, until, the dreaded peril over, it rises slowly as be-
fore, again to expand itself. All this is amply exposed by the transpa-
rence of the most capacious of the cells allotted for the dwelling of these
timid diminutive creatures.

How interesting is the view of a luxuriant specimen of the Sertula-
rian race, — one resembling the richest productions of the vegetable crea-
tion, shorn of its flowers and foliage in the winter season. Now the whole
is still and lifeless : it seems hastening to decay, — to approaching dissolu-
tion. Let it remain undisturbed, and in a few moments it will be covered
by innumerable animated blossoms, issuing forth from their cavities to the
light. Then, after seeking their enjoyments in the plenitude of evolution,
do they again vanish in instant retreat. Infinitely more than mere sensa-
tion, however, is manifested by this marvellous host. All have a common
perception of what affects their common condition, while each has an inde-
pendent sense, deduced by some comparative means, of the real circum-
stances peculiarly afiecting itself.

All the inorganic parts of the Sertularia are of a tough and elastic
texture ; they are hollow, and occupied by a kind of pith, less evident
than in the Tubularia indivisa. During its subsistence, the more minute

140 ZOOPHYTES.

structure of these parts, the articulations and whirls, are obscured, which
has induced naturalists finding them, exposed with the death of the pro-
duct, and still permanent when it was preserved, to seize their characters
for the basis of arrangement.

But the consistence of the body of the creatures belonging to the
Sertulariae is apparently not remote from that of the hydra proper, al-
lowing some difference between those of hydraoid and ascidian formation.
Although these tenants of the zoophytes be liable to perish from natural
or accidental causes, their parts are by no means simply gelatinous, void
of coherence and tenacity. Many of the ascidian are bound by ligaments
to the interior of the cell, which aid their rise and descent ; and in some,
as the Alcyonidium parasiticum, the connection being ruptured, hundreds
drop entire from their cells when the salubrity of the surrounding element
is vitiated.

The nature of the asteroid zoophytes is different. The body of the
hydra, rather fleshy, there forms an integral portion of the common sub-
stance belonging to the whole, from which it cannot separate by decay.

From this diversity of consistence, whereon diversity of structure is
concomitant, these minute beings are endowed with a very different share
of strength and tenacity of life. Those denominated helianthoids, as the
Actinia, are the strongest of any comprehended among the race of zoo-
phytes. They are void of a place of shelter ; but some of the Sertularian
hydrse can scarcely endure speedy transference to a fresher element. Re-
moval from their native abode is generally fatal after the shortest season.
Zoologists should thence value the correct delineation of perfect speci-
mens as an accession to their knowledge of the animated world.

The life of the specimen is dependent on the subsistence of the pith ;
the life of the hydra on its connection with the body, but not of the con-
tinuity of the pith in the stem or in the other tubular parts. The life of
each of a thousand individuals, though all sustained by diverging parts,
supported on a single common stem, as rising from the root, is independent
of that which animates all the rest. Though all may have been generated
from elements reposited in the pith, whence their origin has been derived,
the death of no one individual seems to affect its neighbour. While the

SERTULARIA. 141

parts above and below are in absolute decay, an intermediate branch may
exhibit all its vigour in luxuriant efflorescence. In the natural state, the
decay commences with the lower ramifications ; in an artificial state, the
extremities of the various parts rather seem the first to perish. This cer-
tainly ensues with various species, when its rapid progress is always de-
structive of the specimen. Nevertheless, the subsistence of vigorous ani-
mated extremities may be long, and their reproductions numerous, while
all the lower ramifications remain as inert matter, having lost both the
vegetative and the vital principle.

From these reasons, and from constant exposure to accident, as well
as the violence sustained in being withdrawn item their native places, per-
fect specimens of the Sertularia, always a delicate product, in any but the
earlier stages, can be seldom obtained. Almost all have undergone ex-
traordinary mutilation. Neither are any of the largest specimens ever ani-
mated throughout, so that each cylinder, denticle, or cell, contains a liv-
ing tenant. This subsists only in portions of them. Though multitudes
remain many have perished : whether from the distempers or casualties
incident to the least, as well as to the greatest works of the creation. —
Death ensues because life has been. Some elegant specimens, indeed, illus-
trate these pages. The reader would be incredulous were I to tell him
out of how many rejected, or in the course of how many years.

The duration of the life of zoophytes is not easily ascertained, espe-
cially where an individual of a multitude may be replaced by regenera-
tion. If conjectures shall be indulged, it must be from observation of so-
litary animals.

Independently of the preceding injuries from time or accident, the
progress of nature itself proves destructive.

Every compound specimen, even a species which bears a thousand viva-
cious hydrae at once, seems to originate through the medium of a single
individual animal. The Sertularia, Flustra, Cristatella, Virgularia, and the
whole Alcyonic race, exhibit a single polypus, whose existence, in certain
genera, is incompatible with the evolution of posterity from the specimen
whereof it is the foundation.

142 ZOOPHYTES.

Although many hydrse of the Sertularise may survive that progressive
increment of the specimen adding to their numbers, this is utterly pre-
cluded in the Alcyonic masses, covered by a single stratum of asteroid
hydrse, not half an inch high, while the mass consists of half a cubic foot
in quantity. All the lower generations are overwhelmed by those above
them. If I rightly understand the nature of zoophytes exceeding a single
animated stratum, they are enlarged by extension above, not by accessions
below.

The difference between the nascent Sertularia and the adult is often
so great, that, to pronounce their identity would be fallacious. It is the
same with other zoophytes. No one could recognise the Cristatella in the
hydra quitting the ovum, more than the Botryllus, though not yet in-
cluded in this class, in the early stages of its simple ascidian formation.

Among the adults themselves, there is also sometimes such a discre-
pancy, that practised observers may enumerate several as distinct species,
which truly concentrate in one. Farther still, the naturalist may delude
himself in comparing the dead with the living subject. Parts of the latter
disappear with the fulfilment of their functions ; parts of the former are
obliterated. If features alter after an inexplicable manner during life, it
is not surprising that greater changes accompany its cessation.

Thus the vigorous subsistence and the decay of the Sertularise may
occasionally manifest anomalies, precluding all theories on their original
formation and exact definitions of their organic structure : each discloses
some peculiarity unseen in the other. The naturalist will vainly seek those
vivid colours decorating some of the most beautiful subjects, unless amidst
the waters of congenial salubrity. If framing his system on the arti-
culations, whirls, grooves and notches exposed by transparence in decay,
he will find few such guides in vigorous specimens, where they are ren-
dered obscure or indefinite by the opacity of the neighbouring parts, and
only to be shown by death. Neither shall he find in the decayed pro-
ducts whereon most systems repose, those transparent campanulate cells
whither their timorous tenants can retreat for protection, together with those
singular and varied prolific vesicles once loading the most luxuriant pro-

SEETULAEIA. 143

ducts. All have fallen ; for their use being temporary, their subsistence is
transient. Though the pith itself be the chief obstacle to detecting the
minute formation of the inorganic parts of the living specimen, nothing is
less permanent. It totally disappears. Portions of the skeleton alone
remain, after preceding deperdition of life and organization ; for I believe
it to be true, that no more than what are comparatively mere fragments
of the perfect subject continue entire.

If we are to ascertain the nature of the Sertularise, we should behold
them complete, as in every stage, and under every aspect. Endeavouring
to show the peculiarities of healthy, vigorous, and symmetrical animals,
from the figure and arrangement of their mouldering bones, would never
be satisfactory.

After some details on the appearance and properties of various zoo-
phytes, we shall resume a more explicit view of the most interesting points
distinguishing their history.

§ 1. Sertulabia Polyzonias, The Hoop Sertularia, — Plate XXII.
— ^The embarrassment regarding identity, which is very frequent, may
be perhaps avoided, by selecting specimens with prominent features for
illustration and commentary. They are apt to be undervalued if com-
mon, as we forget that what is rarely seen by observers is uncommon in
respect to them ; and that what is very common to us may be elsewhere
scantily distributed. Subjects always at command are generally ne-
glected ; whereas they should be of all others the best understood. At-
tempting to inform our neighbours from a type of absolute novelty, which
few, if any, but ourselves have beheld, would be a futile endeavour.

Probably this Sertularia is designated Polyzonias, from several belts
or rings obscurely encircling the ovarian vesicles.

Specimens rise four inches high, by a stem which is slightly waved.
It is meagrely provided with boughs and branches diverging to right and
left, at irregular intervals, in the same plane, so that the whole specimen
might be sunk in the thickness of pasteboard. Cells are ranged alter-
nately on both sides of the stem and subordinate parts, always originating

144 ZOOPHYTES.

from the convexities by which these are distinguished. They are some-
what ventricose, swelling downwards from a narrower circular orifice,
whereon none of the teeth specified by Lamouroux have been seen,
though several are on the orifice of the vesicles.

The cell is occupied by a hydra with about 24 or 26 deeply muricate
tentacula, which expand about a line between the opposite tips. It is large
in proportion to the cell, whence it protrudes by a long neck or body, and
retreats completely within the cavity. Of all the hydraoid zoophytes, it
may be rated the next in size to that of the Tubularia larynx. But the
dimensions, vigour, and aspect of these creatures are extremely dependent
on the salubrity of their element, and the peculiar state of the atmo-
sphere.

The whole product is of a green colour, of various shades and inten-
sity, which is derived from the pith, as the fistulous inorganic parts are trans-
parent. In earlier stages the green is vivid. The stem of adults, or older
specimens, is occasionally yellowish or brown. I have never observed the
hydrse of any other colour than green, of different intensity.

The meagre appearance of the Sertularia is remarkable. Few speci-
mens are equally luxuriant as the scantily clothed figures here represented,
Plate XXII. fig. 1 ; the same enlarged, fig. 2 ; and most of the branches
are frequently on one side, fig. 3. A stem has sometimes occurred, which,
without having generated any branches, had above 30 alternate cells. One
with 29 was 15 lines high, whence their dimensions and intervals may be
computed. A large bough had 35 on each side, these being the most nu-
merous ever observed.

The food of the smaller compound zoophytes is problematical ; but it
is obvious that all must have subsistence to sustain life, and promote en-
largement. I was induced by the size of the hydra here to attempt feed-
ing them with soft particles of the mussel, a substance the most grateful
of any to most of the lower carnivorous tribes ; and I believe that I suc-
ceeded. I thought the particles might be discovered in the remoter parts
of the stomach, whither they were transmitted by a distinct channel.
There the contents appeared as a dark internal mass, becoming ovoidal.

SERTULARIA. 145

and the hydra distorted. If the particle be too large, it is retained a long
time externally ; nor can it be forcibly removed without the visible reluc-
tance of this diminutive being.

Some authors speak of such creatures as the Animalcula inficsoria
being absorbed by the Sertularian, Foliaceous, and Lunate Zoophytes.

Moderate light and heat, and especially the renovated element, in-
vite protrusion of the hydra from the cell to enjoy their refreshing influence,
fig. 4. Pertinacious retreat is frequently preserved, perhaps from the
state of the atmosphere, as during a cloudy sky, or the greater chill of a
north wind ; or an invisible slough may be separating somewhat like that
of the Actinia.

Probably the hydra retreats within its cell to die ; but the life of each,
being independent of the rest, the death of one does not affect its neigh-
bours.

The ovaria, or vesicles of this Sertularia, are large in comparison of
the cells, and of singular structure, being as if composed of united hoops
or belts. The orifice of some is serrated. — Plate XXII. figs. 5, 6.

Prolific vesicles are rare ; indeed, specimens with any vesicles are far
from common.

Several with living hydrse, and with vesicles scantily distributed, full
of yellowish corpuscula, having occurred in September, seemed to promise
progeny. All except two had discharged their contents in a few days, as
an ovoidal or globular mass, about a line in diameter, adhering to the ori-
fice. The mass consisted of from 17 to 20 pale yellow spherules, im-
bedded in the most transparent albuminous matter. Some were quite
globular, even under the microscope ; of smooth, uniform, shining surface.
Others were less regular. But nothing resulted from any of them. —
Figs. 7, 8.

At the distance of several years, the subject was illustrated more sa-
tisfactorily. Specimens with lively hydras, and bearing vesicles, scantily
distributed as before, were obtained in July. Only one vesicle appeared
among twenty cells ; however, three were on a twig. Those prolific ex-
tended a line ; the orifice serrated, and the cavity crowded with yellow

VOL. I. T

146 ZOOPHYTES.

corpuscules, altogether resembling a bag of small shot under the microscope.
Some vesicles contained 24 at least. — Plate XXII. fig. 6.

About 50 planules issued from the vesicles on the eighth of July, the
specimens having been procured on the day proceeding. These animals
were nearly a third of a line in length ; the body plump, approaching ro-
tundity, somewhat flattened below, of a smooth uniform aspect, and darker
in colour than straw-yellow. In course of their escape, they were ob-
viously suspended from various parts of the specimen by an invisible thread ;
but when reaching any solid surface, they advanced with an equal, gliding
motion, resembling that of Planarise. The observer could not associate
them with any other genus in the St/stema Naturce. No external organs
could be detected by the most careful microscopical inspection. They
assumed various forms, according to circumstances, and, as afterwards
established, these were modified also, according to the period of their ex-
istence.— Fig. 9.

Many planulse continued quitting the vesicles from the 8th until the
12th of July. They spread on the bottom, and crowded together on the
sides of their vessels. Numerous dark green, thick, obtuse spines were
rising from spots on the bottom, on the 14th of the month. Several were
enlarging as buds next day, which had developed as a hydra from some
others of them.

In the course of their progress, the spine is dark green, thick and ob-
tuse ; in further advance, the summit, enlarging, exhibits the hydra as
a green bud within its cell, the spine becoming the sustaining stalk ;
also the green colour of the stem, shows a central pith, contained in a
sheath of considerable width. — Figs. 10, 11.

A nascent hydra had 16 rather long and slender muricate tentacula ;
the orifice of the cell was somewhat oblique.

Prolific specimens having been committed to a vessel on the 10th of
the month, were withdrawn on the 14th. Numerous planula) quitting the
vesicles congregated at the bottom, and now at least 60 spines had rose,
that is, in four days from the time of their leaving the vesicles. But
farther progress was slow. No second hydra had been generated against

SEETULARIA. 147

the 31st of August, which was the latest survivance of any of the first
from the spine.

The contents of the vesicle, though apparently fresh and entire, when
discharged in a mass, may prove abortive, as previously stated. The sphe-
rules, which should have become planulse, are then retained amidst the
albuminous mass, which has been expelled more probably by some aerial
expansion, than by an organic animal faculty.

A residuum frequently occupies the empty vesicle, having discharged
its embryonic contents, which is of uncertain nature, fig. 5, a. We can
scarcely consider it some organization, generating an'elastic fluid, to burst
the pellicle closing the mouth of the vesicle, if there be one, or otherwise
promoting expulsion.

Illustrations of the process of progressive increment are obtained
from this species of Sertularia in its earliest stages, besides those aiForded
by the young bred from the vesicle. An enlargement appears at the
summit of a stalk, which is found to be invested by a delicate thin film,
including twin buds composing it. These are unequally advanced ; but as
the lower matures, its higher companion forks off, and then another from
this latter, the higher. The buds are nascent hydrse in their respective
cells, each having, apparently, its own peculiar integument, within the
common filmy involucrum.

Rapid growth ensues. A young specimen, with only a single head on
the 4th of October, had acquired six on the 20th, besides a seventh in
embryo. Now, it had rose about seven lines.

A few facts regarding the evolution of the hydra and the regenera-
tion of the product, were shewn by older specimens.

One consisting of a main stem and a single lateral branch, each
extending about six lines, was selected for observation on March 9. —
PI. XXII. fig. 13. At that time it rose no higher than b. In the even-
ing, four of its hydrse, e, e, e, e, displayed themselves from their cells on
the stem a, b, and two days after, six on the branch c, d. Thus ten living
hydraj then subsisted. But some of them generally lurked in conceal-
ment, for the temporary display of a whole colony is rare, though occa-
sionally seen, even where very numerous, if circumstances be favourable.

148 ZOOPHYTES.

Nine appeared on March 21 ; ten on the 23d ; eleven on the 24th ; but
none on the 26th. The branch c, d, was decaying on April 17, and had
perished on the 30th.

Probably the stem had been mutilated of a higher portion than b,
previous to my acquiring it. At this point, a new organization, proving
to be two originating buds, appeared on May 3, and one of them displayed
a hydra on the 6th. Thus, at least 58 days from the commencement of
observation had been required for the evolution of this new animal.

Other two were displayed on May 9 and 11 :, AU three,/ g, h, mani-
fested great vigour : and they subsisted until the 23d. Next day, the
24th, h still appeared. Thus the preceding hydrse survived about 14 days,
none of them being displayed afterwards.

But, in the close, a new germination proving a hydra, was unexpec-
tedly generated from the cell, i, near the root of the main stem, which
contiimed flourishing until June 9. The higher portion was now in
decay.*

Regeneration of the hydrae also ensued in another specimen.

PI. XXII. fig. 14. On April 4, this consisted of a single stem, rising
about six lines, with ten hydrse displayed, besides two cells, a, b, then va-
cant. Likewise a bud, consisting of two embryos, was far advanced at
the summit, and these were displayed as perfect hydr« before the 16th.

Next, the cell b, previously vacant, generated a hydra, c, which, along
with that above it, had decayed on June 9 ; and the upper portion of the
stem folded down in decay over the lower portion.

While in this state, a regeneration of the stem shot up through an
aperture in the fold. A new hydra also issued from one of the old cells, d.

The forking of two buds appeared at the summit of the regenerated
stem, on July 11 ; they were flourishing along with a third on the 18th,
and a fourth was displayed on the 26th.

During survivance of the regenerations above, vitality seemed extinct
below : Nevertheless, a new hydra issued from e, the highest but one of

* The latest regenerations may not be represented if the drawings were completed
previously. The subjects are represented aa appearing at the date of their execution.

V.l.

PL.XXJl.

p|-r?i

.V::^^;s^?:::::

k^^Ai/a^ay^^:^:^^^^-^-

SERTULARIA. 149

the old portion, which, with its collateral embryo, flourished on July 27.
They continued displaying themselves until the first of August, when the
course of observation was interrupted.

It is difficult to render this part of the subject more explicit without
a series of delineations. But, in abstract, it concentrates in the fact, that
the hydrse once replenishing the cells, are replaced after their decay by
others.

Although so powerful a reproductive faculty resides in the Sertidaria
polyzonias, no satisfactory issue has attended experiments to obtain it from
artificial sections.

As common to many of the race, prolongations are generated natu-
rally from the lower extremity of sections, whether the specimen be
flourishing or vacant.

Among other facts resulting from the preceding observations, it ap-
pears : —

I. That the regeneration of the hydrse, and of defective parts, some-
times ensues in the Sertularia polyzonias.

II. That a period of not less than 58 days may be requisite for bring-
ing the dormant principle to maturity as a living hydras.

III. That propagation of the species is effected through the medium
of certain corpuscula generated in the vesicles, which issue forth in the
form of active planulse.

IV. That not fewer than 24 are sometimes contained in a single
vesicle.

V. That the whole contents, as imbedded in a gelatinous substance,
may be expelled from the vesicle, and prove abortive.

Plate XXII. Fig. 1. Sertularia polyzonias.

2. The same, enlarged.

3. Branch, shewing the predominance of lateral vegetation.

4. Extremity of a branch with hydrse.

5. Relative dimensions of a vesicle, a, and a cell, b.

6. Prolific vesicle.

150 ZOOPHYTES.

Plate XXII. Fig. 7. Prolific vesicle, having discharged its contents in a mass,
proving abortive.

8. Another.

9. Planulse from the vesicles.

10. Nascent Sertularia originating as a spine from a planula.

11. The same, farther advanced, with the hydra budding in

its cell.

12. The same ; the hydra now mature, displayed from its cell.

13. Specimen illustrating the regeneration of hydrse.

All the figures of this Plate, except the first, enlarged.

§ 2. Sertularia Abietina — The Fir Sertularia. — Plates XXIII.
XXIV. XXV. — Perhaps no animal product is exempt from individual
distinctions, if those which are inscribed as the nearest kindred exhibit
peculiarities. When such peculiarities are decisive in several, they con-
stitute a species; and where some common features apply to several
species, they are united as a genus. It is only by examining a number of
specimens that the facts are discovered ; but much difference of opinion
must ever subsist as to what distinctions are sufficient to establish either
genus or species ; and it is not to be denied that superficial views have
misled many naturalists. The presence or absence of an organ, the posi-
tion and number of the various parts, their supposed use, their transience
or permanence, have been all leading guides. Varieties are determined
from the fainter differences.

The Sertularia abietina is thus named from its resemblance to some
kind of fir, in conformity with the practice of comparing objects less
known to those more familiar.

It rises nine or ten inches high, by a slightly waving stem, with
branches diverging from each side in alternate arrangement, so that the
extreme expansion of the product is about three inches, somewhat above the
root. The branches shorten upwards, in proportion to their height on the
stem, until only a single alternate cell borders the highest. The sides of the
whole stem from the root to the summit, and of all the branches from the
origin to their extremity, are clothed with a row of cells, also in alternate

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('fuirlcsTfttmisci Sculp'

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SERTULARIA. 151

arrangement. This peculiar arrangement is the true formation of the
adult, though the cells sometimes appear nearly in pairs. About 45 cells
are on each side of the longest branch, and one on each side of the short-
est. The branches issue from the convexities of the stem. An elegant
recur vature, as of an ostrich feather, distinguishes this product, which is to
be ranked among the larger flexible zoophytes. As all the parts diverge
in the same plane, a specimen such as described might be sunk in the
thickness of ordinary pasteboard. — Plate XXIII.

The cells, which are ventricose, or swelling in the middle, are inha-
bited by a grey or white hydra, protruding a long cylindrical neck and
head, with about 24 muricate tentacula. These tentacula appearing to
the eye a little enlarged, like so many rows of beads, environ a hemi-
spherical central pouch. The hydra is quick and active, but not readily
obtained alive. At least the proportion has been small amidst a number
of specimens.

The species occurs in considerable profusion in the sea, at the depth
of several fathoms, commonly rooted on old deserted shells. As if dwell-
ing in society, many specimens are often found in close approximation.
Those of larger dimensions are profusely invested by a minute, testaceous
animal, the Spirorbis, or by another zoophyte, the Cellaria, or Crista
eburnea.

Recent living specimens are universally of a yellowish colour — honey-
yellow ; others, like many marine productions, have acquired an unnatural
reddish hue.*

Naturalists understand the figure of the ovarian vesicle as a specific
character of the Sertulariae ; but this opinion must be received under mo-
difications sometimes perplexing, and yet insufficiently explained.

Vesicles are either simple or compound, that is, consisting of a single
pod, with its contents, affixed immediately to the specimen, or of one
more complex, being a pod sustained by an intermediate organization.

* The nomenclature of colours employed here is from a work on that subject by the
late Mr Peter Syme, an accomplished artist, founded on one by Werner. Many drawings
were executed for me by that artist.

152 ZOOPHYTES.

Numerous simple and compound vesicles are crowded together on the
branches of the Sertularia abietina. The former are ovoidal, like those of
certain other Sertulariae.— Plate XXIV. fig. 19; XXV. fig. 1. The
latter consist of a hollow spherule, with an elevated vertex, sustained on a
ventricose pedestal, considerably smaller, this pedestal bearing some resem-
blance to the ovoids. Eight or ten such compound vesicles, close in a
row, may be compared to apples on the branch of a prolific tree. —
Plate XXV. figs. 2, 3 ; Plate XXIV. fig. 3.

The same specimen sometimes bears both the simple and the com-
pound vesicles.

Each kind of vesicle contains a single, vivid yellow corpusculum, in
as far as I have been able to ascertain.

To determine the nature of the corpusculum, two branches,.each with
numerous compound vesicles, were suspended in a tall glass cylinder on
the 1st of May. Eighteen planulae could be enumerated at the bottom
on the 10th of that month. These seemed nearly half a line long, round,
one extremity obtuse, the rest tapering almost to a point, the surface
smooth and uniform, of a beautiful vivid yellow colour. Altogether, this
subject resembled a minute pear. — Plate XXIV. fig. 4, a, b, c : enlarged,

A, B, C.

Some were observed on the side of the vessel. Their peculiar shape
and evident solidity seemed unfavourable to ascent.

Another portion of the same Sertularia had been consigned to a ves-
sel wide and shallow, so as to be accessible to the microscope — always a
necessary precaution when intermeddling with diminutive objects. Here
two or three similar planulse appeared also, on the 10th of May, and on
the 12th other two or three. Small yellow spots were seen besides. On
May 13, three nascent Sertulariae, all yellow, could be recognised ; one
rising as the prominence of a flattened spherule ; a short spine issued from
another : and from the third spot a spinous prolongation shot up about two
lines, with the summit slightly enlarged. Towards next evening this en-
largement was forking ofi" nearly at right angles to the prolongation now
seen to be a stem, which rose still higher, and it was evidently acquiring
the figure of a cell. At this time the summit of the stem was likewise

SERTULARIA. 153

swelling slightly, which augured similar configuration as the other. —
PI. XXIV. figs. 5, 6 ; fig. 7, enlarged.

The root, also, was losing its density. At first an opaque, flattened
spherule, it becomes a thinner spot : ramifications diffuse within its circuit,
very conspicuous in early stages, but growing daily fainter and less dis-
tinct, until disappearing in attenuation. On May 15, the under surface of
the spot had broke into five ramified processes, which I can scarcely com-
pare to radicles, some of them apparently preparing subdivisions, all deep
yellow, darker towards the centre, and paler towards the extremities, these
being still bounded by a circular outline, fig. 8, enlarged.

The nascent specimen, fig. 7, had acquired a second cell on May 15,
a third on the 22d, and soon afterwards a fourth. Many stems had two,
and a few had three ; but this specimen vegetated no farther, — Figs. 9,
10, 11, 12. Natural size, and enlarged.

Recurring to the tall glass jar, wherein eighteen planulse were enume-
rated upon the bottom, on May 10, all were motionless on the 14th,
though next day five or six still showed symptoms of animation. On this
day, also, some bright yellow spots, each -wiih a central spine, appeared
just about the place the planulae had occupied ; but none could be disco-
vered on the side of the vessel.

Being less versant then, in the history of Zoophytes, from practical
observation, the relation between the living planulae, endowed with volun-
tary motion, and the stationary spots substituted for them, were to me very
perplexing.

All the spots with a central spinous process were affixed to the bot-
tom of the vessel ; but my perplexities were aggravated by next day ob-
observing a short spine shooting from the summit of several of the com-
pound vesicles on the suspended branches.

Under the microscope, these spinous processes corresponded with the
subjects of previous observation. Nothing farther was seen but the vas-
cular pedestal, bearing the spherule, whence the yellow spine issued,
which was not evidently connected with either the pedestal or the branch.
— PL XXIV. figs. 13, 14 ; spherule, a ; pedestal, b, enlarged.

Besides these globules, from which a spinous process issued, a stalk
VOL. I. u

154 ZOOPHYTES.

with two buds protruded from each of other two globules still suspended.
The evolution of their hydrse ensued on May 21, when favourable micro-
scopical observations ascertained, that the animals, of a grey colour, were
each provided with about 25 deeply muricate, almost moniliform tentacula.
They were of lively nature, enjoying the element, and seeking a safe re-
treat in their cells. It was easy to identify them with the hydrse of the
adult product, which had borne the vesicles.

At this early stage, the real structure of the Sertularia afterwards
disguised by supervening opacity, is admirably exposed : And here is
shown, in an especial manner, the great advantage of examining living
beings under every aspect. The stalk issues visibly through an aperture
in the summit of the spherule. Its dark yellow pith is clearly followed
upwards through the transparent tubular stem, until dilating above into
the young hydrse, while the extremity of the tube itself is enlarged into
cells, sufficiently capacious for their tenants. — Fig. 15. The spherule yet
rests on its pedestal, though here intercepted from view.

The cells are generated simply by prolongation of the tube, and they
stand in alternate arrangement, diverging to right and left in the same
plane. But this prolongation is dependent on the vigour of the pith, for
its presence is the indication of vitality. The evolution of the hydrse, in
relation to each other, is successive. Thus the lowest flourishes first, and
next that above it. As the cell seems derived entirely from the tube, so
does the hydra seem to originate exclusively from the pith. The cell, once
formed, does not depend on the subsisting of the hydra, at least in this
species of zoophytes, but in some of the campanulate (Sertularian) zoo-
phytes, the cell is not permanent.

The prolongation of the stem of the Sertularia abietina, is always in
proportion to the successive generation of cells. One bearing only two,
is of about equal length to three cells and a half Deviations from regu-
lar arrangement frequently occur among nascent Sertularise.

Many young specimens had now two hydrse, with their cells, on
May 24. An embryo, still immature, darkens a third cell, during the
growth of this Sertularia, fig. 16. One had three hydrse, May 25, which con-
tinued in beautiful display until June 27, fig. 17 ; only a single specimen ac-

SERTULARIA. 155

quired four. Its progress is shown in figures 5, 6-9, 1 1, somewhat exceeding
the natural size, and the three latter figures, 7, 10, 12, enlarged. This
same specimen had three cells on May 22, and next day four ; and so it
continued until July 25, when delineated ; but decay prevented maturity
of the fourth.

During observations protracted for several weeks on all the nascent
Sertularise, fewer and fewer hydrae protruded from their cells, and this
chiefly in proportion to the lapse of time from their origin. Several ap-
peared on July 18 ; in another week only one, though the cells apparently
still contained living inmates. Sometimes these creatures, and indeed
the tenants of all Sertularise, persist in long retreat. When induced to
issue forth by renovation of the limpid element, they speedily retire to
their respective dwellings, after a transient display.

It is obvious, therefore, that two differently formed vesicles are borne
by the Sertularia abietina, a fact also incident to a few other Sertularia;.
The precise nature of the pedestal I have been unable to ascertain ; but
circumstances infer that it may be possibly an ampuUate or flask-shaped
vesicle originally, whereon the other spherule is generated. Specimens
have occurred with vesicles resembling the ordinary ampullate vesicle of the
Sertularia or Plumularia falcata, and scarcely in less profusion, though of
inferior fecundity. About 26 or 27, almost in a double row, with con-
tents nearly white, were crowded towards the side of a branch not an inch
in length.— Plate XXV. fig. 1.

Other specimens of the same group bore a compound vesicle, with a
pedestal as those above described, the spherule containing a single yellow
globular corpusculum, the pedestal vascular as before. — Plate XXV.
figs. 2, 3. Planulse of a fine saffron yellow issued from the spherules,
about half a line long, the head obtuse, and the tail pointed, but not
alike pyriform until beginning to contract, when some resemblance to those
already represented ensued. — Fig. 4.

Here the reader should be apprized that great diversity occurs in the
shape of the same planulse, from whatever zoophyte they come. Nothing
can be more variable than their soft, extensile, and contractile bodies, in
motion or at rest ; and according to the freshness of their element or the

156 ZOOPHYTES.

temperature of the atmosphere, — and especially when about to undergo
the metamorphosis incident to their race.

One planula, fig. 4, having become quiescent, a spine rose from it,
which being sufficiently prolonged, exhibited two buds, almost mature, on
May 1. The planulse of the same brood were only advancing in the ve-
sicles on the 19th of April.

The evolution of the nascent Sertularise, from vesicles in situ, is a
rare occurrence. We have seen that, from some unnatural retention in
the cysts of the Tubularise, the organs of the young may begin to unfold.
This may tend to corroborate and explain a figure given by Ellis, repre-
senting a hydra issuing from a vesicle of the Sertularia pumiln. But it is
to be noted also, that examples are not wanting of portions of the Sertu-
larise vegetating through an empty vesicle, vsdth a generated or regenerated
hydra. I can account for it only from the sudden metamorphosis fre-
quently rendering the planula motionless, and thus precluding its escape
from the vesicle. But although this may ensue in the Sertularia abietina,
the discharge of the planula from the vesicle, to undergo its metamorpho-
sis unrestrained, is the ordinary and natural course whereby the species is
perpetuated.

It is doubtful whether the vesicle is a permanent part of the organi-
zation in any of the mature prolific Sertularise. Here the foundation of
the compound vesicle, PI. XXIV. figs. 3, 13, 14, b, becomes more and
more unstable, until at length its adherence to the branch appears to be
preserved only through the medium of adventitious matter. Did the
nascent Sertularia originate regularly in the vesicle, while subsisting, and
were it still retained there during the fall, its fixture would be intercepted
from some more solid foundation below, which could not but prove inju-
rious. Therefore, evolution of the hydra within the spherule of the com-
pound vesicle seems the result of unnatural retention.

Young hydree have survived about a month. The Sertularia abietina
is not uncommon, but such specimens as that represented are rare. Some
consist of a greater number of subordinate parts.

SERTULARIA. 157

Plate XXIII. Sertularia abietina.

Plate XXIV. Sertularia abietina.

Fig. 1. General arrangement of the parts.

2. Cells and hydrse of an adult, enlarged.

3. Compound vesicles, in situ. Spherules containing yellow corpus-

culse, a ; vascular pedestal sustaining the spherules, h, enlarged.

4. Planulse from the spherules, a, b, c ; enlarged, A, B, C.

5. Nascent Sertularia, with the first cell advancing.

6. Nascent Sertularia with two cells.

7. The same, enlarged.

8. Root of a nascent Sertularia, enlarged.

9. Nascent Sertularia, with three cells.

10. The same, enlarged.

11. Nascent Sertularia with four cells.

12. The same, enlarged.

13. Nascent Sertularia. The rising spine shoots through the summit of

the spherule of a compound vesicle, a, on its pedestal, J, enlarged.

14. Another of similar description.

15. Nascent Sertularia, with two hydrse, the stem having shot up from

within the compound vesicle, a, enlarged.

16. Another, farther advanced, enlarged.

17. Another, still farther advanced, having three hydrse, enlarged.

18. Arrangement of the cells, enlarged.

19. Prolific simple vesicles, enlarged.

Plate XXV. Figs. 1-5. Sertularia abietina — details.

Fig. 1. Branch with ordinary ampullate or flask-shaped vesicles ; enlarged.

2. Branch bearing compound vesicles.

3. The same, enlarged.

4. Planulse from these compound vesicles, enlarged.

5. Planula metamorphosing ; now a spherical segment with a central

spine, enlarged.

§ Jj. Sertularia abietinula — Diminutive Sea-Fir. — Plate XXV.
figs. 6-13. — ^The narrow resemblance of this to the preceding species is
such, that it might be almost supposed the same in an early stage, or
a variety in miniature. But I have been unable to identify the two ;

158 ZOOPHYTES.

nor caa I identify the present subject as the Sertularia filimla, or any
other yet described. Therefore the appellative it now receives must prove
either provisional or permanent, according as future observation shall de-
termine.

The shades of distinction separating some of the zoophytes are small ;
their own formation is variable and indefinite, and they are in so many
varieties, that very erroneous conclusions may lead us to diversify species,
while the subjects passing through slight discrepancy of structure shall at
length merge in one.

The Sertidtiria abietinula generally appears from one to two, or per-
haps three inclies high. Branches originate near the root, diverging and
diminishing after the fashion of the former, and, like it, they are provided
with few subordinate parts. — Plate XXV. figs. 6, 7. The whole are bor-
dered by low denticles or cells, nearly in pairs, from which hydrae, with
about 18 tentacula, are displayed. Branch enlarged, fig. 8.

Irregular articulations subdivide the inorganic parts, comprehending
five or six pair, or sometimes only a single pair of cells. The contrac-
tion of the stem at the articulation, under the pair of cells where it is
formed, is considerable.

For the most part, simple ampullate vesicles are dispersed over the
branches, wherein the elements of the progeny are generated. These are
seen as a bright yellow corpusculum of irregular form. — Plate XXV.
figs. 9, 10.

When a specimen had been a few days in my possession, the vesicles
under that aspect discharged their whole contents, perhaps prematurely,
which now exactly resembled, in all respects, what is above described of the
premature discharge from the vesicles of the Sertularia polyzonias. A
transparent gelatinous mass remained adhering to the orifice of the vesicle,
among which, instead of a single object as I had previously supposed, there
appeared from one to six vivid yellow corpuscula, still of somewhat irregu-
lar form. The substance wherein they were imbedded was scarcely percep-
tible ; and, indeed, at one particular place, unless for the vicinity of the
yellow corpuscula to the branch bearing the vesicle, the connection of the
jelly with its mouth could not be known. — Fig. 11, a.

SEETULARIA. 159

None of the corpuscula proved to be spherical or of regtdar shape,
under the microscope. But when viewed within the vesicle, the contents
then appearing a single irregular corpusculura, may present that charac-
ter, from the compression of several together.

Exact uniformity did not prevail in the vesicles of fig. 7. One had
a kind of short spinous prolongation, fig. 12. In other specimens there
was no sensible distinction, fig. 13.

This product usually occurs on old empty shells. I do not recollect
to have found it on other substances.

Certain desiderata yet remain to render its history explicit.

Plate XXV. Fig. 6. Sertularia aUetinula.

7. Group on a shell.

8. Branch of fig. 7, enlarged.

9. Vesicle on a branch of fig. 6, enlarged.

10. Prolific vesicle.

11. Vesicles discharging yellow corpuscula amidst albuminous

matter, enlarged.

12. Vesicle of fig. 7, enlarged. •

13. Vesicle of fig. 7.

§ 4. Sertularia rosacea — Lilt/ Coralline. — Plate XXVI. Figs. 1-13.

^This is a delicate product, generally pure white, or of the faintest grey

colour : it rises two inches, or somewhat more, in height, by a stem per-
pendicular, or slightly recurved, from which boughs diverge, either in the
same plane, or from around the circumference. Sometimes these are at
right angles to the stem. Subordinate parts are few. — Plate XXVI.
Figs. 1, 2. Articulations are seen at irregular and distant intervals, but
only in decaying specimens ; for they are inconspicuous in those which are
vigorous, and the parts occupied by the pith.

The whole stem, together with all the subordinate parts, are clothed
with long wide cells, disposed in pairs ; and all the extremities terminate
in a similar pair, mature or elementary, fig. 3. The cells incline outwards.

160 ZOOPHYTES.

Many have a slight curve or elbow in the middle ; and the orifice is gene-
rally oblique.

The hydra is light grey, provided with about 22 muricate tentacula,
surrounding the low closed orifice of the central pouch. It is very lively,
protruding a long and slightly tapering neck far beyond the mouth of its
cell, which is extremely transparent, and it retreats suddenly within. —

Fig. 4.

While in vigour, numerous hydrse, in all their vivacity, fringe the
branches of this product ; but their existence is brief in confinement ; and
when internal decay has consumed the pith, along with the living tenants
of the cells, only a diaphanous skeleton is left behind.

Large and peculiar vesicles, alike difiicult to be described and repre-
sented, are borne by the Sertularia rosacea, without any regular distribu-
tion. In some places they are single, elsewhere rather in pairs, or some-
times several in a line are crowded together ; and they are interspersed with
living hydra; on the same portion of the specimen, fig. 5. Their trans-
parence is extreme, for they are scarcely visible by the microscope. All
are fashioned somewhat like a tall vase, ribbed longitudinally by lines a
little darker than the sides. Each enlarges upwards from its origin, and
near the summit contracts by a mucronate smaller orifice, formed of points,
shaped very differently in different specimens. — Figs. 7, 8, 9, 10.

Prolific vesicles occur in the summer months, May, June, and July,
when they contain three or four white or yellow spherules above, towards
the widest part, and sometimes appear sustained on a pillar within, fig. 9.
The spherules unfold as a diminutive planula, not exceeding the fourth of a
line in length, which issues from the orifice of the vesicle. These creatures
are occasionally seen traversing their prison as they approach maturity,
apparently seeking an exit, which is precluded by an invisible barrier.
Having departed, they prove, like others, of variable form, move, be-
come stationary, distorted, and undergo the wonted metamorphosis. —

Figs. 11, 12.

The planulse, from specimens obtained on May 1, had all metamor-
phosed to different stages on the 11th. Some consisted of a stem with a

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SERTULARIA. 161

lonnf clavate summit. Others had two buds under a common involucrum.
Two days later one had a hydra with 15 tentacula, and two buds preparing
above it. — Fig. 13.

In these young specimens, although the pith seems confined within
its own peculiar channel, a wider cortical covering apparently forms the
stem around it.

This product usually occurs as a parasite on other zoophytes ; and it
is often involved by the Spongia coalita, spreading rapid destruction around
the precincts of its vegetation.

Plate XXVI.

Fig. 1. Sertularia Fosacea.

2. Prolific specimen.

3. Branch with hydrse.

4. Hydra and cell.

5. Branch with hydrse and vesicles.

6. Section with hydrse and vesicles.
7-10. Vesicles full and empty.

11. Planulse from the vesicles.

12. Planulse from the vesicles.

13. Nascent Sertularia bred from a planula.

All the preceding figures, unless figs. 1, 2, enlarged.

^ 5. Sertularia pumila, Sea Oak Coralline. — Plate XXVI.
Figs. 14-21. — This diminutive product occurs in considerable abundance as
a parasite on some of the marine fuci ; likewise it grows on rocks and stones.
The Fucus serratus is most profusely invested by such quantities as almost
to weigh down the leaves, when nearest to ebb tide.

Larger specimens rise an inch high, by an erect stem, from which a
few boughs and branches, in the same plane, issue almost at right angles to
their principal part. The whole is of greenish colour, and generally of
rather a meagre aspect. — PI. XXVI. figs. 14, 19. All the parts are bor-
dered by a row of cells, which are arranged in pairs. Each pair forms a
division or articulation, somewhat heart-shaped. — Fig. 16, enlarged. The

VOL. I. X

162 ZOOPHYTES.

orifice of the cell opens simply from it, without any tubular prolongation.
A white hydra, with about 19, and sometimes a greater number of tenta-
cula, deeply muricate, protrudes its long neck from the cell. — Fig. 15.

Two kinds of vesicles have been observed on this Sertularia, — the one
ovoidal, fig. 18, — ^having expelled its abortive contents ; the other globu-
lar, fig. 20. The contents of the ovoidal vesicles are white or yellow.
Some faint yellow planulse have issued from the former, on the first of
August, which offered nothing remarkable. — Fig. 21. The contents of the
globular vesicles are yellow. No semblance of circulation could be dis-
covered in the hydra.

A powerful vegetative faculty resides in the stem, insomuch that a
prolongation, shooting down from a section, has been rooted in a night.

Much irregularity pervades this species, of which diiFerent specimens
exhibit varied aspects, in the number and dimensions of the parts, as well
as in the number and distribution of the vesicles. Sometimes one or two
of the latter appear at a remote interval : sometimes several are closely
huddled together, on or about the stem.

The facility of obtaining the product, however, renders it a conve-
nient subject for observation.

Plate XXVI.

Fig. 14. Sertularia pumila.

15. Specimen with ceUs and hydrse, enlarged.

16. Articulation consisting of two cells.

17. Ovoidal vesicle discharging its abortive contents.

18. Empty ovoidal vesicle on an articulation.

19. Specimen with globular yellow vesicles,

20. The same, enlarged.

21. Planulse from ovoidal vesicles.

All the figures except 14. and 19. are enlarged.

§ 6. Sertularia Halecina and Cognates — Herring Bone Coralline.
Plates XXVII. XXVIII. XXIX. XXX.— It appears to be very obscure
what is the true Sertularia halecina specified in the Linnsean Systema

SERTULARIA. 163

Naturee, or in other systems ; or whether authors have in fact identifie d
any one of such peculiar formation as to be exclusively thus denominated.

The figure given by Ellis, Plate X. a, N. 15, as the Sertularia hale-
cina, is certainly from an indiiferent drawing of what is named Thoa
Beanii in Dr Johnston's useful work, Plate VI.

Thus the description and concomitant figure by Ellis do not distin-
guish any species recognized as the Sertularia halecina exclusively.

But there are several reasons for assuming that this species is seen
under considerable modification, which has induced naturalists to esta-
blish as others, what may be perhaps only varieties. Some of these are
certainly cognates — children of the same family.

Whatever may be the real critical distinctions among them, many
interesting facts are disclosed by perfect specimens falling under observa-
tion. Therefore, while abstaining from all further controversy on the
point, which can be of little importance to most readers, I shall speak only
of a few individual corallines by this general name, which have occurred
from time to time in the course of my investigations into the nature of
zoophytes.

1. Among several specimens obtained on the last of December, one
arose four inches high by a brownish stem, composed of aggregated tubuli,
with large boughs diverging to right and left, each of which might be cir-
cumscribed by an isosceles triangle. This peculiar formation distinguished
the other specimens, as it does also those consisting merely of a stem with
diverging boughs, void of farther subordinate parts. All the boughs stood
at an acute angle with the stem ; likewise the branches with the boughs ;
and still more conspicuously the numerous twigs on each side of the
branches, — the whole of these parts being in alternate arrangement. The
prevalent colour of this specimen was greenish. Some very slender and
diminutive, apparently mature white parts, are frequently seen on speci-
mens, which seem neither spurious nor parasites. Though the stem be
compound, the more remote organization, in as far as sensible, resolves into
simple tubes. — Plate XXVII.

Hydrse of the wonted form, with 18, 20, or 22 muricate tentacula

164 ZOOPHYTES.

issued from tubular cells, at the end of the twigs, which were encircled by
a succession of ruffs or frills at intervals.

All the preceding specimens were laden with vesicles.
The common features of the product seem a compound stem of tubuli ;
subordinate parts in alternate arrangement rising at an acute angle with
the principal parts ; hydrse issuing from tubular cells terminating twigs
distinguished by successive frills. It has always appeared doubtful, after
innumerable observations, whether the hydra, being once extruded from
the tubular extremity of the twig, preserves the faculty of again retreating
completely within.

During earlier stages the stem is waved, and then, as in new acces-
sions, the subordinate parts rise from the salient angles.

The discrepant aspect of different specimens is so great, as to occasion
much embarrassment in determining the identity of species, or of conclud-
ing them varieties.

In endeavouring to explain the formation of this Sertularia, it must
be observed, that the succession of ruffs or frills seen in the finest speci-
mens, is not to be held as a definite character, especially if assumed as of
a precise number. The hydra appears to be regenerated more than once
from the same twig, and it is probable that each regeneration is accom-
panied by a circular enlargement, as a frill, of the orifice of the cell. Cer-
tain parts of a small specimen having been vacant of hydrse on the 5th of
April, had generated about a dozen on the 12th, besides others advancing.
—Plate XXX. fig. 8, enlarged.

Under favourable circumstances, the progress of such hydrae is well
exposed through the wide transparent sheath inclosing the pith, fig. 9,
where the head appears like a compact, solid substance at the extremity ;
then altering its shape gradually, until completely displayed, fig. 10. It is
now discovered that the pith issues from the branch, and that the orifice
of the first cell is under the disc of the hydra. If there was one from
each cell previously in fig. 10, the hydra must have been close to the
branch. The nature of such frilled intervals is also very explicit from
Plate XXIX. fig. 2.

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SERTULARIA. 165

New shoots originate from the most unlikely places. Thus a speci-
men above two inches high, quite vacant of hydrae, bore two minute
sprigs with hydrae, the longest rising but a line and a half, all of vivid
green. — Plate XXX. fig. 11, enlarged.

Where vigorous hydrae already subsist, the regeneration of others ad-
vances in their vicinity — the clear and transparent sheath showing their
progressive evolution. Nothing can be more interesting than to witness
the rapid refinement of an embryo hydra into perfect configuration, and
the display of the organic parts actually completed under the observer's
eye. My notice having been directed to a specimen wherein, from the
highest of three frills, a dark green globular mass rose prominent as an
acorn in the cup : in an hour it became someM'hat clavate, while turned
slightly aside, still enlarging without any indications of tentacula. But in
another hour these organs became perceptible, through a very delicate
transparent involucrum protecting the mass. The head had now pro-
truded almost entirely from the frill, and the extremities of the tentacula
separating, having improved the symmetry of the parts, they were gra-
dually and at length freely unfolded two hours afterwards in their due pro-
portions. The new head of the finest green was perhaps the fourth which
the twig sustaining it had borne in succession.

The hydra seems to develope as an enlargement of the summit of the
internal pith, and bursts an integument on attaining perfection. Probably
the budding Sertularia, like the budding Tubularia, is always thus invested,
though extreme tenuity, added to the intimate application of the parts,
may conceal its presence. In the Tubularia it is more conspicuous. Na-
ture is careful to protect the tender organs of her originating productions,
with an external covering suitable to their condition.

The extent of reproduction is indefinite ; but presuming that succes-
sive frills indicate new evolution, it occurs no less than six or seven times.
Specimens with three or four such as Plate XXIX. fig. 2 are frequent.

A vigorous reproductive faculty resides in the Sertularia halecina and
its cognates, which is often displayed in another form, by vegetation from
the extremities of sections. These coming in contact with a solid surface
have a tendency to adhere, and to extend in irregular prolongations, sur-

166 ZOOPHYTES.

passing the natural increment. They are then pale, and bear some short
spinous twigs at distant intervals, from whence hydrse are generated.

Propagation. — There is no absolute uniformity in the size, shape, or
colour of the vesicles borne by what I consider the type of the Sertularia
halecina, if this distinction shall be allowed.

All the preceding specimens, of December 31 [p. 163], were laden
with vesicles, Plate XXVII. ; and what is now to be remarked in regard
to them, has been also witnessed in many others.

The vesicles were of diverse characters, even of irregular shape ; gib-
bous, or with a hump on the green parts of the Sertularia, Plate XXIX.
figs. 3, 4 ; likewise grey ovoidal vesicles on the grey parts, fig. 5. But
some green specimens have both gibbous and ovoidal vesicles, as figs. 7, 8.
The vesicles shewn on fig. 6, were borne along with ovoidal vesicles ; and
the grey parts bore such as resembled figs. 9, 10, on the same branch.

The different figure of these vesicles is seen still more distinctly in
delineations of them, from green specimens of the Halecina and its cog-
nates.—PI. XXX. fig. 1 ; PI. XXXI. figs. 4, 5, 7. The orifice of the
one is in the hump ; of the other in the extremity.

It is obvious, therefore, that vesicles of different formation are borne
by the Sertularia halecina.

The vesicles of some specimens are green exclusively. — PI. XXVII.
Of others they are exclusively yellow. — PI. XXVIII. fig. 1. The grey
parts bear white vesicles.

As usual, the vesicle is the matrix wherein several planulae, from
whence its colour is derived, are brought to maturity ; their numbers are
commonly two, three, or four, in each.

The specimen, PL XXVII., produced both green and white planulije,
undistinguished by any features to render them remarkable. Many of the
ffreen were crawlinsr in a smaller vessel, a, on the 13th of January, from
which I shifted the specimen next day, to a wide shallow vessel, b. Many
also appeared in the latter, on the 17th ; and they had augmented to above
100 on the 18th, all pale green, A group, on the 20th, consisted of the pla-
nulae, in every stage of animation and incipient metamorphosis, PI. XXIX.
fig. 11 : the natural form being a, b, c ; two others were contracting, and

SERTULAEIA. 167

a short spine rising from a third. The same vessel likewise contained an
irregular substance, rather larger than a contracted planula, from which
several spines were issuing next day, and which proved to have been
originally some combination of the elements of young Sertularise.

On January 13, many planulse, discharged from the vesicles of this
specimen, PI. XXVII., were crawling in the vessel a, above referred to
from which this specimen was removed next day. All the planulse were
converted to roots with spines on the 20th, the latter unequally advanced,
some being scarcely perceptible. It then appeared to me that the spine
was prolonged from the smaller extremity of the planula. The diffusing
root spreads with considerable regularity where only a single planula under-
goes its metamorphosis, PL XXIX. figs. 12, 13, 14, 16 ; but it is some-
what irregular where more than one are in approximation, as fig. 16.

The nascent product was variously advanced on the 24th, — such as a
spine with a root not yet diffused, fig. 17 ; or crowned by a growing bud,
fig. 18 ; enlarged, fig. 19. There were also two rising from a root diffused
irregularly, as above, in fig. 16 ; together with a hydra, and a bud from
another, fig. 26 ; and one specimen with two hydrse, fig. 21. The hydrae
of fig. 16, had each 18 tentacula; the front of one of them enlarged,
fig. 1. It is unnecessary to say more of the brood in the small vessel re-
ceiving the specimen. — PL XXVII. originally.

This same specimen was transferred to a larger vessel, b, on Janu-
ary 14, wherein many planulas appeared on the 17th, as above said.
Having undergone their metamorphosis, a number of nascent Sertularise
had two hydrae flourishing on the 31st of the month, or two and a bud :
and one, the farthest advanced, had three. Therefore, the specimen with
three, had reached this stage of maturity, from the planular state, in about
a fortnight.— PL XXIX. figs. 22, 23, 24.

Certain anomalies occur among a numerous brood. The regular pro-
cess of propagation is the discharge of a planula from the vesicle, its con-
sequent activity ; the cessation of motion, diffusion of the root, and a spine
rising with an enlarged summit, which is next displayed as a hydra. But,
sometimes no sensible spine rises above the diflfusing root, thence further
progress is arrested ; and sometimes, though the planulse be productive,

168 ZOOPHYTES.

there is no regular difflision. The spine rises from a socket, with an ir-
regular extremity, fig. 25 ; and it advances so as to bear hydrse, by simple
prolongation, without diffusion, securing it below. — Fig. 26.

All these facts have been illustrated by a variety of observations made
throughout the course of many years, and at different seasons of the year.

No essential distinctions farther than might be expected from the
mutable form of soft-bodied animals, are seen among the planulae.

A specimen with green hump or gibbous vesicles, such as PI. XXX.
fig. 1, produces green planulae, figs. 2, 3. In all, where the regular pro-
cess ensues, the root breaks into divisions, fig. 4 ; with originating stalks
and nascent hydrse, figs. 5, 6. Some of these products are less regular,
though all with pith, occupying a wide sheath, fig. 7, as previously ex-
plained.

But the observer is very liable to be deluded by peculiarities, the same
specimen exhibiting hydrae from an orifice scarcely elevated above the
branch which bears twigs with frills and hydrae, quite distinct and separate
from them. There is also a most conspicuous difference in the form of the
vesicle ; for some green specimens bear both ovoidal and gibbous vesicles ;
and grey specimens or green specimens bear both ovoidal vesicles, and
such as are of a very different character, as in Plate XXIX. fig. 6, already
adverted to. While the green vesicles produce green planulae, fig. 11, the
grey vesicles produce grey planulae, fig. 27. A few specimens bear a long
green prunate or plum-shaped vesicle, which I have never seen in such
maturity as to afford any produce. — Plate XXX. fig. 12.

The principal external difference sensible in complete adults is in
some bearing green vesicles, as that of Plate XXVII. on the larger parts,
and white or very light grey vesicles on the slender white parts, and in some
bearing yellow vesicles exclusively, as that of Plate XXVIII. fig. 1. This
latter was a fine and prolific specimen, the hydra pale green. The vesicles
were in hundreds. Beautiful yellow planulae issued from them about the
middle of May, in such numbers, that, rising on the side of the vessel, their
accumulation formed a yellow ring just under the surface of the water,
fig. 2. A multitude of Sertulariae sprung from them, the furthest advanced
of which had thre6 hydrae and a bud on May 26.

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SERTULARIA. 169

The profusion of nascent Sertularise is sometimes very great. Above
300 were rooted on the bottom of a small vessel in a preceding year, on
the 5th of February, from green specimens.

Facts of difficult explanation occur in the history of the Sertularia
halecina, such as regenerating bydrffi shooting up through the empty vesicles,
PI. XXIX. figs. 28, 29. Examples of this occurred in April. Some of the
vesicles on specimens were empty ; one or two hydrse were displayed from
others. These must have issued from the pith of their respective twigs,
which had certainly vegetated through the vesicle, from the stem, after its
formation, and probably after having discharged its contents. It is not un-
likely that some generation or regeneration of this kind may have induced
naturalists to credit the developement of hydrae in the vesicle, which, if it does
ensue, is only by deviation from the natural course, as signified previously.

2. Among the cognates of the Sertularia halecina is one designated
by Dr Johnston Thoa Beanii. Lamouroux seems to have discarded the
Halecina from its place among the Sertularice ; and, if I understand his
work, to have constituted a new genus of it named Thoa, comprehending
two species.

This, the Thoa Beanii, rises three inches or more, by a stem com-
posed of aggregated tubuli, together with boughs, branches, and twigs, all
like the former, diverging on each side in alternate arrangement, but
sometimes irregularly distributed. — Plate XXXI. fig. 1.

The adult is of a brown or olive colour ; young specimens are white.
The hydra of older specimens is green or greenish ; but if the specimen be
young it is white, as also from parts newly generated. It has 20, 22, or
24 muricate tentacula, for the number is not uniform ; and when the pro-
duct is in greatest perfection the hydra issues from the extremity of a tu-
bular twig, having from two to seven frills, like those parts recently de-
scribed. But on the same specimen may be sometimes seen twigs both
without frills and with them. They are quite transparent in very small
specimens, and always prominent where present. — Plate XXXI. figs. 2, 3.
The hydra extends far from the orifice of the tube, when enjoying the
freshness of its element, and retreats partially within if annoyed. There is
here no proper cell.

VOL. I. Y

170 ZOOPHYTES.

The vesicle, in its most decided form, terminates by an ovoidal extre-
mity ; and a prominence, with a circular lip, rises from about the middle,
or towards the end, fig. 4 ; living hydrse and prolific vesicles are contem-
porary on the same specimens, fig. 5. The vesicles of some specimens have
chiefly contained four embryos, fig. 6, which, on maturity, as planulse, seek
an exit through the orifice of the circular lip, fig. 7. Having escaped,
they traverse their vessel with the swelling head foremost, according to the
nature of their race.

But the regularity of their planarian form is gradually impaired as
the vigour of motion relaxes, fig. 9. They become quiescent, and a stem
rising from above, indicates a nascent Sertularia.

On the 16th of October, specimens of this Sertularia, bearing white
vesicles, produced planulse of the purest white, very minute, the head much
enlarged and obtuse. They swam supine, as most others do. The tempe-
rature at the time was extraordinary for the season. Others continued
issuing from the vesicles, and after several contained in one of these gra-
dually elongating from their globular form, and departing, two of perfect
shape remained, which visibly followed through the circular lip, fig. 7, a.
The orifice was then first discovered to be there, and not in the extremity,
h, as I had conjectured.

Various white spots were consequent on the escape of the planula?,
the first bearing a hydra on the stem, eight days from the date of their
production. The same interval elapsed on a different occasion.

In the course of other observations, specimens with a brown stalk and
white vesicles, wherein I thought six embryos could be discovered, were
set apart on September 30— the vesicles being of the preceding peculiar
formation. Numerous planulae appeared in the vessel in 48 hours, and
several spines rising from circular spots on the bottom. Many nascent
Sertularijfi, each consisting of a single hydra, were flourishing on the 5th
of October. Thus, only six days had sufficed to bring them to maturity,
computing from the discharge of the planulse from the vesicle.

Numbers of planulae were produced on this occasion, all pure white,
of fleshy aspect, and not a third or a fourth of a line in length. They
swam supine, and when dying without metamorphosis, they decomposed
into granulated matter, such as follows the death of the planaria proper.

SERTULARIA. 171

In respect of time, the progress of metamorphosis seems irregular,
nor am I aware of any precise rules by which it is governed. Sometimes
the circular spot speedily follows the departure of the planula from its
prison. About 50 planulse appeared on the bottom of a vessel with ve-
sicles on the 4th of November. All these had ascended the side next
day, and almost as many replaced them below. Numerous circular white
spots with spines appeared on the 7th of the month, both on the sides and
on the bottom of the vessel.

3. Until some learned naturalist, by the aid of the skeleton, and of
living specimens, shall determine the absolute distinctions of the species
here assumed as the Sertularia halecina, the following remarks are meant
as generally applicable to the whole indiscriminately.

All rise from the root by a darker or lighter white, green, or brown
stem, which consists in adults of aggregated tubuli. Renovated extremi-
ties or recent generations are pale green or white, the rest of the speci-
men being some hue of the preceding colours. The whole subordinate
parts are in alternate arrangement. Originally the twig hardly rises above
the larger member sustaining it : and it may remain alike low at a greater
age. But it also appears so much prolonged as to exhibit from two to
seven frills.

The hydra issues from the highest of these frills ; but it is not retrac-
tile entirely within the tubular part of the twig. It is greenish or white.
Adults, or those of larger and older parts, have from 20 to 24 tentacula.

Hydrae are regenerated from the same twig. A powerful reproduc-
tive faculty also generates shoots from the lower extremity of sections con-
taining the elements of hydrae subsequently developing on them.

Numerous green or yellow vesicles of varied form are distributed over
specimens. One about 30 lines high, and expanding as much in breadth,
was laden by above 400 yellowish vesicles, dispersed over the boughs and
branches, with a few up to the very summit on the stem. The yellow of
the vesicle in contrast with the green of the other parts, rendered this di-
minutive product an elegant type of a fruitful tree. The form of the vesi-
cle is much diversified. In some the orifice is at the extremity ; in others
a circular lip opens from a prominence near the middle.

172 ZOOPHYTES.

The colour of the vesicle is derived from its embryonic contents —
developing as planulis, which, expelled from above, crawl away on reach-
ing the bottom of the vessel below.

Prolific vesicles continue discharging planulae during two or three
weeks.

The planula, like that of other species, becomes motionless, and con-
tracting in a circular spot, a spine rises from the centre, at the summit of
which a hydra is advancing, while the root, diifiising below, breaks into
divisions. This may be very distinctly seen by providing a watch-glass for
reception of the planula, and reversing it as the course of metamorphosis
proceeds. Sometimes the young Sertularia is seen floating inverted, with
the root upwards, while in a very early stage, from having been acciden-
tally detached in the commencement of metamorphosis.

The original spine extending as a stem, seems to consist of a single
tube, very wide, formed like a skin or sheath, around the internal pith,
when we may plainly discover that the extremity from whence the hydra
issues has no cellular enlargement. — PI. XXX. fig. 7.

The hydrae are developed progressively ; some being always less ad-
vanced. They are displayed originally without any definite number of ten-
tacula, such as may be distinguished as the complement of the race.
Either 17, 18, or 20, for the most part belong to them. In fig. 7, as
above, which is not so regular as many others, the one hydra had 17, the
other 20.

An example occurred of the nascent zoophyte showing three hydrae
within nine or ten days of its production, as an active planula, from the
vesicle.

Although originating Sertularise follow the escape of the planulae, by
the natural process, whole colonies disappear without such a result : and '
they may resolve into the granulated matter above alluded to, concomi-
tant, likewise, on the dissolution of Planariae, or of some other semi-ge-
latinous animals.

Disturbing the planulae seems to impair the process of effectual meta-
morphosis.

Prolific vesicles and living hydrae appear on the same specimen, but

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SERTULAEIA. 173

the mode whereby the vesicle and its contents are generated is problema-
tical. When vigorous hydrse seem to originate from twigs rising through
the centre of vesicles, it might be presumed that the vesicle has origina-
ted on the orifice of a twig opening from or sustaining it ; or, that the twig
sprung up after the contents of the vesicle were discharged.

After preservation for some time, the pith of the extremities exhibits
symptoms of decay, which, in descending, impairs the reproductive faculty.

The hydrae are very susceptible of external impressions. I have ob-
served the whole of a specimen, amounting to an hundred, with the tenta-
cula closed up of a gloomy morning.

Many circumstances concur in rendering these Sertulariae, whether
varieties or not, favourable for general observation. I doubt not that
other naturalists may ultimately show distinctions, which I have been un-
able to detect among them.

Plate XXVII. Sertularia halecina. Adult specimen with green vesicles.

Plate XXVIII. — Sertularia halecina.
Fig. 1 . Adult with yellow vesicles.

2. Yellow planulse from the vesicles, enlarged.

3. Two nascent Sertularise from the planulae, enlarged.

4. Nascent Sertularia, farther advanced.

5. Nascent Sertularia, still farther advanced, having three hydrae dis-

played.

6. Nascent Sertularia with three hydrse.

7. Nascent Sertularia with three hydrae and a bud.
All the preceding, except fig. 1, enlarged.

Plate XXIX. Sertularia Jialecina — details.
Fig. 1. Front of a young hydra, enlarged.

2. Hydra protruding from a twig, with frills.

3. Portion of a specimen with green hump or gibbous vesicles, en-

larged.

4. Extremity of a branch with vesicles.

5. Ovoidal grey vesicles.

174 ZOOPHYTES.

Plate XXIX. Sertularia halecina — details.

Fig. 6. Hump or gibbous vesicles, borne along with ovoidal vesicles, on the
same specimen.
7-8. Vesicles of different figures on the same specimen.
9-10. Vesicles borne on the grey parts of a specimen.

11. Planulse from the green vesicles of the specimen. — PI. XXVII.
12-15. Diffusing root of nascent Sertularise.

16. Hydrae generated from two planulae, approximated in their meta-

morphosis.

17. Spine and root in an early stage.

18. Budding spine and root.

19. The same, more enlarged.

20. Nascent Sertularia with a diffusing root.

21. Nascent Sertularia with two hydrse.
22-24, Young Sertularise bred from the planula.

25. Spinous projection from each side of a root.

26. Sertularia originating from an irregular root.

27. White planulse from grey vesicles.

28. Regenerated hydrse issuing through vesicles.

29. Regenerated hydrse issuing through vesicles.
All the preceding figures enlarged.

Plate XXX. Sertularia halecina and cognates.

Fig. 1. Branch of a green specimen with gibbous vesicles.
2, S. Planulse from these vesicles.

4. Diffusing root viewed from below.

5. Nascent Sertularia, with a hydra and a bud, bred from the planula.

6. Nascent Sertularia farther advanced, with two buds.

7. Nascent Sertularia from a planula, showing the diffusing root ; also

the pith within a wide sheath.

8. Specimen which regenerated a number of hydrse.

9. Regenerating hydrse not yet unfolded.

10. Branch of a specimen with hydrse.

11. Regenerated hydrse springing from an old branch.

12. Green prunate vesicles [p. 168].

Only figs. 5, 6, are of the natural size.

SERTULARIA. l75

Plate XXXI.

Fig. 1. Sertularia (Thoa) Beanii.

2. Hydra.

3. Branch with twigs and frills.

4. Branch with vesicles.

5. Hydrse, and prolific vesicle.

6. Prolific vesicles.

7. Planulae about to quit a vesicle by the orifice a.

8. Planula liberated.

9. Planulse metamorphosing.

All the figures except fig. 1, enlarged.

§ 7. Sertularia muricata. — Plate XXXII. — In a depauperated
state, the resemblance of this product to the Sertularia halecina is such,
that we are prone to number it among the cognates ; nor, until the pecu-
liar substances which naturalists have denominated vesicles be proved pro-
lific, do I feel altogether disposed for its exclusion.

The Sertularia muricata rises four or five inches high, by a stem com-
posed of aggregated tubuli. Its boughs, branches, and subordinate parts,
all diverge from each side of their principals in alternate arrangement. —
Plate XXXII. fig. 1. The hydra, provided with about 22 or 24 muri-
cate tentacula, issues from the tubular extremity of a twig distinguished
by frills, whither it seems to have only a partial retreat, fig. 2. The stem
of the adult specimen is brown ; the hydra is green ; and the whole pA»-
duct presents quite the character of the Sertularia halecina exhibited in
Plate XXVII.

Various parts of this zoophyte, in its better state, are invested by pe-
culiarly formed capsules or vesicles, cotemporary with the living hydra,
and sometimes in vast profusion. Perhaps they exceed the multitude of
the vesicles proper to other Sertulariac, nor do they seem restricted to any
particular part. The stem is often entirely covered by clusters huddled
together in confusion.

This inorganic substance, if it be a vesicle, somewhat resembles a
flattened filbert, attached by the shortest pedicle to the stem or branches

176 ZOOPHYTES.

of the Sertularia, fig. 3. Its margin is serrated, or divided into obtuse
jn-ocesses, which also cover the surface, fig. 4. No regularity prevails in
the dimensions ; large and small vesicles are in close approximation ; their
colour, apparently derived from the contents, is greenish or yellowish.
They are transparent when empty.

Though I have had many specimens at various seasons of the year,
which were preserved with every possible care, the opaque vesicles became
empty and transparent, without discharging any visible object. All my
endeavours, which were not few, to discover the nature of their contents,
have been defeated.

At different times I have been induced to question whether these in-
numerable muricate bodies, thus investing, even totally obscuring, the parts
beneath them, are truly vesicles, or whether they are not rather extraneous
substances. I conjectured them to be the capsular progeny of some of the
Testacea, especially from the almost invariable presence of a minute solen,
concomitant on that of the vesicle ; and which may be seen crawling on
the same twig, bearing both vesicles and living hydrse, as well as crawling
on the sides of vessels with specimens, and on other parts, fig. 5, a, l>.
However, nothing has hitherto verified that conjecture ; nor have I heard
that the mode of propagation of the Sertularia miiricata has been deter-
mined by observers.

Plate XXXII. Fig. 1. Sertularia muricata.

2. Hydra enlarged.

3. Portion with muricate vesicles, enlarged.

4. Vesicle magnified.

5. Portion with a hydra, a ,• and a minute solen, i, enlarged.

§ 8. Sertularia (Plumularia) falcata. — The Sickle Coralline. —
Plates XXXIII. XXXIV. — The arrangers of the Systema, finding the
multiplication of species inconvenient, have endeavoured to rectify it by
the strange expedient of erecting some of the species into genera, and for-
tifying that project by a new name, as if nomenclature, instead of physio-
logy, were the foundation of permanence. Thus a few have been selected

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SERTULARIA. 177

for enrolment as PlumularicB, a few as Campanularia, and so on of others.
This would be a laudable and a useful plan were it profoundly laid — were
the distinctions so prominent and exclusive as to show a positive transi-
tion ; but where they are slight or equivocal, they must be accounted of
little avail.

Of this the subject of the present paragraph offers so strong an ex-
ample, that recent authors debate whether it should be removed from the
Sertulariffi. The point is unimportant.

The product is of delicate and elegant structure ; its general configu-
ration resembling a series of feathers implanted in spiral arrangement
around a slender stem, which rises about twelve inches high. These
feathers, like branches, extend from an inch and a half to two inches,
shortening in proportion to their height on the stem : each consists of
from 20 to 30 twigs, arranged alternately on the sides of the rib, and also
shortening regularly in advancing towards the extremity. A slight gene-
ral recurvature of the points characterizes the whole product, much tend-
ing to its elegance and symmetry, which, to be duly appreciated, requires
the presence of its native element, waving amidst it ; the height of the
finer specimens being 300 or 400 times the diameter of the stem, pre-
cludes it from sustaining itself without the aid of the water.

The branches are neither in pairs, in sets, nor strictly in spiral ar-
rangement on the stem ; two or three, nearly in a vertical line, are above
each other ; and then, two or three, somewhat off that vertical line, above
them, thus producing the apparent spiral exhibited by the position of the
whole.— PL XXXIII.

The adult is yellowish and opaque ; but, regenerated parts are pure
white. Though occurring in great profusion, this product can be seldom
procured entire, thus compelling the naturalist to represent smaller spe-
cimens or their extremities, for the sake of showing them in greater per-
fection.

The Sertularia generally rises by a single stem, whereon the branches
above described are implanted. It is rarely of such luxuriance as to pro-
duce so large a limb as the lesser division appearing on the figure.

It will be observed that what I denominate a branch, issues imme-
diately from the stem ; that it is composed of a rib, from each side of

VOL. I. z

178 ZOOPHYTES.

which the twigs issue in alternate arrangement. The upper surface of
each twig is clothed with two rows, somewhat apart on the surface, of al-
ternate minute low denticles or cells, inhabited by very minute pure white
hydrse, having 15 or 16 muricate tentacula. The extremity of a branch,
with its tenants, is represented as seen by the microscope. — PL XXXIV.
fig. 1.

Both the organic and inorganic parts, I mean the skeleton, together
with the hydra and its cell, are regenerated in the Sertularia falcata. The
whole twigs of a specimen five inches high, bearing 24 branches, had suf-
fered mutilation. But above 100 parts, with several hundred cells and
hydrse, all pure white, were regenerated in March and April. A great
contrast distinguished these reproductions from the older portions.

During spring, especially in March and April, and in the beginning of
May, numerous white or yellow vesicles load the Sertularia, each colour
belonging to its respective specimen ; the two never being interspersed on
the same specimen. The vesicle itself is perfectly transparent. Thus its
colour is derived from the contents ; but the yellow has always appeared
larger than the white. Numbers of the yellow crowded together on a
branch, perhaps 30, 40, or even 50 at a time, resemble so many minute
lemons both in shape and colour. — Plate XXXIV. fig. 2. There seems no
difference in the profusion of the white and the yellow, and the cells in the
neighbourhood of either are occupied by living hydrae. Both are like an
ovoidal flask, with a short tubular neck and a circular orifice, some having
a margin or reflected lip, fig. 3.

The side of the vesicle is of such transparence as to expose what is
within, and there from one to seven corpuscula may be enumerated. —
Figs. 4, 5, 6.

Having selected portions of the Sertularia, with a number of yellow
vesicles for a regular series of observations, I remarked some slight move-
ment among the contents. The general configuration, the relative posi-
tion, and the aspect of the included subjects, were changing ; and in fif-
teen miiautes the separation of one corpusculum, which rose above the
other, proved its animation. It ascended slowly towards the orifice, and
issued forth as leisurely ; but when reaching the surface of the glass below,
its course was sufficiently accelerated. This animal was of vivid yellow

SERTULARIA. 170

colour, as while contained in the vesicle, not exceeding the third or fourth
of a line in length, and during progression, shaped somewhat as a double
cone or shuttle, but becoming linear as its motion relaxed.

Having heard some accomplished naturalists dispute the animation of
the beings which are here designed planulse, I am now describing, as pre-
viously and as I mean to do subsequently, such facts as bear testimony
of it. We cannot be too scrupulous in admitting what seems an absolute
metamorphosis without unchallengeable evidence. On weighing the import
of the whole, the reader can exercise his own judgment.

This active motion of these and other planulse indicated the presence
of some external organs whereby it was effected. Yet on subjecting many
of all kinds to the microscope, none such could be discovered. Neither
have I been able to detect any cilia or ciliated apparatus on the contents,
whether more or less mature, of the most transparent vesicles of the Ser-
tularise. Possibly the powers employed were insufficient ; but we know
very well, at the same time, that the vermicular tribes are capable of very
speedy motion without similar external auxiliaries, that mere undulatory
alterations in the body are enough.

No planulae had appeared on April 26, in a vessel set apart with spe-
cimens of the Serhdaria falcata on the 23d ; but 30 or 40 were seen next
morning. Several corpuscula also occupied the bottom, and a very few
were floating — circular under the microscope, of a greyish-yellow tinge, and
about a third less than the extended planulse. The number of planulse
increased so much next day, that portions of the vessel seemed yellow from
their accumulation : many moving swiftly, others were contracting, fig. 7.
On the 5th of May not one could be seen.

Meantime nascent Sertulariae were springing every where, but chiefly
on the bottom ; they were also on the sides, some as high as the surface
of the water. Many vesicles now appeared empty ; yet the numerous
brood still continued to be so much augmented, that although the vessel
could not have contained above three ounces of water, at least 200 origi-
nating Sertulariaj were dispersed within it on May 13.

Spines rose as usual from circular spots ; cells were generated on their
summit, whose tenants, perfectly white, exhibited a long neck, and about

180 ZOOPHYTES.

fifteen deeply muricate tentacula, on maturity. Two, three, four, or five
cells were developed successively on some specimens. None acquired a
greater number. — Figs, 16, 17, 18, 19, enlarged ; also fig. 27, which is little
larger than life.

In another course of observations, many short spines were rising from
the yellow spots, in five days after the prolific vesicles had been set apart ;
and in two more days their nascent Sertularise had two, three, even indi-
cations of a fourth cell, all yellow. Thus they had attained such maturity
in eight days.

The period is very irregular, for the yellow spots have appeared as
suddenly as 24 hours from the escape of the planulse ; also, on one occa-
sion, above 40 yellow spots were distributed throughout a vessel within 72
hours, during which interval 60 active planula3 had quitted the vesicles.

Prolific specimens having been lodged in a vessel on April 30, pla-
nulse appeared on May 4, and spots next day. Another portion of the
same collection of specimens was set apart on May 7. Nothing could
exceed their fertility ; they were laden with fine bright yellow vesicles,
which discharged their planulse under the observer's eye. In 24 hours, at
least 20 circular yellow spots could be seen at the bottom, while many
yellow planulse, some of them double the size of their fellows, were in mo-
tion. On May 13, not fewer than 70 animals, of various dimensions, and
in various states of incipient metamorphosis, all vivid yellow, appeared at
the bottom of the vessel — almost the whole vesicles then being empty.

Thus the nascent Sertularise originate speedily, for they become firmly
rooted within 24 hours of quitting the matrix.

Such changes as now described are great and striking. The motioji
of the vigorous planula in all directions is swift, though it is not swimming ;
the diffusing root, rising spine and unfolding hydra, look, as it were, the
conversion of an animal to a vegetable product.

Yellow vesicles having been set apart, hundreds of planulse soon after
strewed the bottom of a vessel on the 25th of April, rendering every
part of it quite yellow. Very few continued in motion two days later.
Some were much contracted, others nearly circular. The water being re-
newed, all were transferred to a different vessel. Numbers now began to

.■^/i\^C:^r

*

m

SERTULARIA. 181

move ; and the whole, not under 150, collecting towards one part of their
new habitation, then remained quiescent. Fifteen or sixteen days subse-
quent to their departure from the vesicles, their colour remained as vivid
as ever ; but the microscope betrayed an extraordinary change of configu-
ration. Most of the brood had crowded together ; many extended on re-
novation of their native element, and pursuing their course, they seemed
to be occupied among neighbouring muddy particles, as if in quest of some-
thing there. But, at this time, all were clumsy and disfigured ; some irre-
gular, some truncate, others almost spherical — some not half the size of
symmetrical animals. — Figs. 8, 9. Had it not been for uninterrupted obser-
vation, no one could have identified these distorted beings with the original
perfect planulse, Plate XXXIV. fig. 7.

Some of the original brood survived 27 or 28 days, though much con-
tracted . Their vivid colour remained unfaded long after the symptoms of
animation had ceased.

I have been unable to discover any essential difference relative to the
facts disclosed by the pure white planulae occupying the vesicles of the
Scrtularia falcata, and those afforded by the yellow. On the 7th of May,
many of the white escaped from vesicles within which no motion had been
sensible on the first of that month. They resembled the yellow exactly,
only seeming of rather inferior size, Plate XXXIV. fig. 10, enlarged. But
while inspecting this figure, it must be noted that the shape of the planul*
is liable to perpetual modification ; it is dependent on many circumstances
— temperature, time, age, as well as the will of the animal. The form of
all, when most perfect, is certainly somewhat conical, with a rounded head,
or anterior tapering downwards, and flattened below. Nevertheless, some
appear of more linear form, the sides being parallel, and the extremities
nearly equal, while in complete vigour.

It is established that when yellow planulse occupy the vesicles, yel-
low spots originate on the vessel, and where the planulte contained are
white, the spots following their production are white. The observer, how-
ever, is frequently precluded from following this progress ; he finds them
without witnessing the appearance or quiescence of the planulse. They
originate unobserved.

182 ZOOPHYTES.

Whether white or yellow, they are distributed throughout the whole
interior of the vessels, precisely in such places as might be easily acces-
sible by the planulse. They are often seen in greater profusion on the
sides, just at the surface of the water ; and they are generally found
higher and higher in proportion as the vessel is successively replenished.
If some be seen adhering close to the edge of the water, let the vessel
be still more replenished, others will subsequently adhere above them,
should propagation continue advancing. Meantime, the observer may dis-
cover white or yellow corpuscula floating at the surface, which he would
conclude to be spherules ; but careful inspection proves them inverted
nascent Sertularise, whose root has failed of adhesion.

In all this, it is impossible to avoid admitting the strict analogy be-
tween the preceding stages and circumstances of the progeny of the Me-
dusae, and those distinguishing the early existence of the Sertularise.

Following the design of Nature, it may be presumed that a regular
tendency to adhere, as the planula becomes motionless, is for securing the
diffusion of the root, as a sufficient foundation for the rising product.

Shortly after a glass cylinder had received prolific specimens, nearly
a circle of spots appeared on the sides. The cylinder being emptied and
replenished with water, an inch and a half higher than the circle, eight or
ten spots, also higher, appeared subsequently. Twenty or more of the
lower circle had become affixed in such a manner that their stems issued
downwards ; while the stems of the rest, adhering flat to the side of the
vessel, shot forth horizontally. Spite of that irregularity, some of the in-
verted nascent products acquired five cells ; and hydrse flourished from three
of them. The young at the bottom were numerous ; those on the sides
few. All the vesicles consigned to the vessel were white ; all the planula"
quitting them white ; and all the spots were white likewise.

Adult specimens, with yellow vesicles, having been consigned to a
more capacious vessel, yellow spots were soon after observed on the side,
Just at the edge of the water, or rather above it. Another smaller vessel
being now sunk inside, to raise the water still higher, many additional
spots appeared, within 24 hours, on that part of the side, which the ele-
vated water reaching, had covered. Numerous yellow planulse were like-

SEETULAEIA. 183

wise present. Eight days afterwards, the vessel being emptied and re-
plenished, hundreds of nascent Sertularise were found overspreading the
bottom, and many occupied the sides.

The planulae often show a tendency to ascend, and the root detached
may be borne upwards, which will account for the heights of the nascent
products. Nor is the peculiar curve formed with the side of a vessel by
fluids to be overlooked. At the same time, as in the progeny of the Me-
dusae, there are some principles producing such effects not readily under-
stood.

Considerable disparity appears in the form of the nascent Sertularine.
The root is of the same character as that of others. — Figs. 11, 12, 13, 14.
A spine rises from a circular spot as usual, fig. 15, budding first into one
cell, and then into a second, which is higher. — Fig. 16. The diffusing
parts of the root extend farther, and become fainter with the develope-
ment of the buds. — Figs. 17, 18. At an early stage the stem appears di-
vided by deep-marked, irregular articulations. — Figs. 19, 20. But it does
not appear that any strict uniformity prevails among the different young.
— Figs. 21, 22. Their advance is progressive, denoted by the number of
hydraj and buds. — Figs. 23, 24, 25, 26, 27. I have not been able to effect
their preservation until the evolution of more than five.

From such early decay, it is impossible to discover how that modifi-
cation finally converting this Sertularia into its proper form ensues. The
disparities were so conspicuous, that, until numerous observations ascer-
tained the fact, I found it difficult to reconcile the production of the vari-
ous nascent products to a parent of the same species.

The following general results were obtained : —

I. The Sertularia (Plumularia) falcata is always of a honey-yellow
colour, or nearly so, if adult ; the reproductions are white.

II. Numerous ovoidal vesicles are borne on the branches, during spring,
which, on different specimens, are either pure white or vivid yellow.

III. The colour of the vesicle is derived from the contents, the side
being transparent ; but both kinds of vesicle are never found on the same
specimen.

184 ZOOPHYTES.

IV. The contents consist of five or six corpuscula, — globular in an
early stage, but in a later, relaxing into planulae, which escape by the
orifice.

V. The planulse endowed with the power of expeditious motion, lose
their natural configuration, and contracting in a circular spot, become
stationary.

VI. A spine rising from the spot, enlarges as a cell at the summit,
whence a hydra is displayed, proving the young Sertularia.

Plate XXXIII. Sertularia (Plumularia) falcata.

Plate XXXIV.

Fig. 1. Extremity of a branch with hydrse.

2. Branch bearing vesicles, slightly enlarged.

3. Vesicle with white corpuscula.

4. Vesicles with yellow corpuscula.

5. Vesicles with yellow corpuscula.

6. Vesicles with yellow corpuscula, relaxing in planulae ; one escaping

from the orifice.

7. Yellow planulse from the vesicles.

8. Yellow planulse from the vesicles losing their proper form.

9. Yellow pianulse approaching incipient metamorphosis.
10. White planula from the vesicle, fig. 3.

11-14. Diffusing root from four metamorphosing pianulse.

15. Originating stem from a diffusing root.

16. Stem bearing two buds.

17 18. Stems with two cells ; partition of the roots disappearing.

19. Young Sertularia with a hydra and two cells yet untenanted ; arti-

culations indenting the stem.

20. The same more enlarged.

21. Young specimen with three hydrae, the stem articulated.

22. The same more enlarged.

23-27. Young specimens of varied configuration.

All the preceding figures are enlarged.

SERTULARIA. 185

§ 9. Sertularia (Plumularia) pinnata. — Plate XXXV. — This is a
delicate product, truly resembling a feather. It rises three inches, or little
more, in height, and is generally of a greenish colour. Slender twigs, with
a slight elegant recurvature, issue from each side of the stem in alternate
arrangement, shortening gradually as they ascend or descend from about
the middle of the specimen, and terminate the summit by a mere pro-
jection.—Plate XXXV. fig. 1.

A row of low cells or denticles, somewhat apart, projects from the
convexity of the twig, which, in a certain position, would induce the ob-
•server, by some illusion, to ascribe a spine to the orifice. Each denticle
or cell is inhabited by a hydra, with about 20 muricate tentacula. When
the product is in maturity, there is only one hydra on the twig at the
summit, two on the next, then three, and so on to seven, beyond which
number I have not observed more. The extremity of no part is a hydra,
though it may be preparing from the evolution of one, for the mode of
increment seems to ensue from a twin bud ; the more mature of the twins
unfolding a perfect hydra, and the other advancing beyond it, to deve-
lope somewhat later. — Fig. 2. The cells are low, but quite conspicuous,
fig. 3 ; their tenants show nothing particular. The tentacula are rather
short and stout. — Figs. 4, 5. A waving pith occupies the stem.

Numerous vesicles are huddled together on a portion of the stem,
presenting a reddish or yellowish appearance to the eye from their accu-
mulation. These vesicles are not of uniform figure, the edge of the orifice
of some being even, while two or three prongs extend that of others. —
Fig. 6. Each contains a single yellow or orange corpusculum, fig. 7, which
is discharged as a planula at various seasons of the year, from July and
August to December. — Figs. 8, 9. But all planulse do not seem invariably
of the same colour, as some produced in this last month, from what I con-
cluded the same species of Sertularia, were grey.

The vesicles huddled together on the stem of a prolific specimen pro-
duced yellow planulse, extending about a third of a line, on August 12 and
13. Several crawled along; the motion of others tended to an orbit from
])artial contraction of the body. — Fig. 9. One was monstrous. — Fig. 9, a.
Roots were diffiising from this monstrous planula in a week ; and in a few
VOL. L 2 a

186 ZOOPHYTES.

more days a slender stem, with a bulbous summit, had issued from the
roots. The stem of some others rose in extreme slenderness ; but none
produced hydrse, probably from some accidental cause.

Plate XXXV.

Fig. 1. Group of the Sertularia {Plwmularia) pinnata on a shell.

2. Summit of a specimen.

3. Twig with cells.

4. Hydra.

5. Hydra containing some residuum.

6. Vesicles, as seated on the stem.

7. ProUfic vesicles.

8. Yellow planulse from the vesicles.

9. Planulee from the vesicles ; one monstrous, a, more enlarged.
10. Nascent specimen from a planula.

All the figures of this plate, except fig. 1, are enlarged.

§ 10. Sektularia (Plumulaeia ?) Fascis.— Plate XXXVI.— As this
product participates of various characters whereon the later invented genera
are established, its real position is somewhat doubtful, nor have I had a
sufficient number of specimens in their various states to fix it.

The Sertularia fascis rises four inches or more in height, by a straight,
erect, and rather inflexible stem, under half a line in diameter at the root.
Alternate boughs, bearing very few branches, generally none, are meagrely
disposed around the circumference. A single row of low denticles, for the
most part on one side only, borders the upper surface of the parts, scarcely
projecting above its level, and many of the extremities terminate in a den-
ticle also. On some subordinate parts, a border of denticles appears on
each side, but rarely. The denticles are usually separated by articula-
tions.

The lower portion of the stem is composed of aggregated tubuli like
a faggot, each most probably occupied by its peculiar pith, which substance
is more distinct above, where exposed by the transparence of the single
tubular parts. The waving form of the pith indicates an invisible side or

I

'■

'i

lil

SERTULARIA. 187

boundary, separating it from the lower or under part of the branch. —
Figs. 1, 2.

Above 30 boughs originate from the most luxuriant specimens.

The hydra inhabiting the denticle is retractile completely within,
whence it rises to protrude a long neck, with from 25 to 27 muricate ten-
tacula. It appears somewhat gross, the tentacula stout, and often much
recurved or curled, previous to their full extension. — Figs. 3, 4, 9.

The whole product is greenish, of more vivid colour when young ; the
stem dark umber if old ; and the hydra pale green.

Specimens are founded on old shells. When torn off, a small tuft
separates along with the root.

Probably the stem and subordinate parts are invested by skin, which
is perfectly transparent, and wherein the contraction denoting articulations
is perceptible. However, the structure of the stem itself, farther than con-
sisting of tubuli, and in being porous like wood, is not quite obvious.
These features are seen below in the thicker parts ; but above, the parts
resolve into a single tube.

Regeneration. — While investigating the structure, I cut over some
specimens near the root in December, and subdivided the sundered stalk of
each into several portions. Vigorous reproduction followed. In five days,
seven shoots, about the fifth of a line, or the sixtieth part of an inch long,
were descending from the lower extremity of one of the sections ; and next
day, the prolongation of all still continued advancing in the same direction,
downwards, inverse to that of nature, which is upwards. — Fig. 5.

Shoots more numerous and more vigorous descended also from other
sections. Nine descended from one of them.

Another section, an intermediate portion of a stalk, an inch long,
generated several shoots from both extremities. The vegetation advanced
luxuriantly — more so from the lower than from the upper extremity. Two
hydrse were developed here, and one fi'om a shoot of the upper extremity
in 27 days. This section had been kept in a horizontal position.

Shoots in an early stage are white. The specimens now under expe-
riment had been procured on December 14. A section only four lines in
length was made on the 16th. Vegetation issued from both extremities.

\

188 ZOOPHYTES.

but now the upper portion was the more vigorous. Five shoots were
formed there, bearing eight perfect hydrse on January 17, or 34 days after-
wards ; and from the lower extremity issued three shoots, on one of which
was a single hydra at that date. The section lay horizontally ; each set
of shoots rose perpendicularly. This was an extraordinary regeneration
from so small a fragment.

Among the other reproducing sections, one bad regenerated five
shoots upwards in the natural direction. — Fig. 6. These earlier reproduc-
tions are of a long clavate shape, whether the shoot be generated from the
higher or lower extremity.

On the seventh day following the section, a new shoot or branch was
evidently cleaving from fig. 6, last referred to. Next day, the eighth after
section, a hydra, with a mouth like a cup, environed by 27 tentacula, was
displayed from a denticle on a shoot of the same portion, fig. 7, a ; and on
the ninth day, a second hydra, d, was forking off a, or rather from the site
it had occupied, being then decayed. — Fig. 8. Other two hydrse now ap-
peared from different shoots in the vicinity — whence the progress of repro-
duction from the same section, figs. 6, 7, 8, is shown.

On the tenth day, the extremity of the shoots, a, b, c, fig. 8, had sub-
divided, the hydra, b, still subsisting. — Fig. 9.

The section lay in a horizontal position originally ; and at first its new-
shoots issued almost horizontally likewise. However, by gradually tending
upwards, they became quite erect in twelve days. — Fig. 10. In sixteen,
six hydrse were still displayed ; but in twenty-two, only two shoots, the
taller with three hydrse, remained in display ; in twenty-six, no more than
a single shoot subsisted ; and in three or four longer, the pith was totally
consumed by the progress of decay.

The number of shoots generated from any section seemed to me in-
definite, but I may have been misled by ignorance of the component parts,
because the shoots might correspond to the tubuli. Ten issued from the
stump of a specimen cut low, but only one from the stalk cut high. Each
tube of the stem may be therefore endowed with a separate and indepen-
dent reproductive property, while all resolving into one in the higher parts,
it may concentrate there.

.^WkU

SERTULAEIA. 189

An evident tendency to the nature and form of vegetable growth,
appears in the vertical direction of the regenerations. Shoots double the
length of the shortest section above mentioned, rose perpendicularly from
both ends, as it lay horizontally.

Long ovate vesicles, with a transparent integument, have occurred on
this product in May. I could not observe that they occupied a peculiar
place. Each contained from four to six corpuscula, chiefly spherical, or
tending to this form, and arranged in a curve. They are very seldom
found, and an intervq,! of eight years having interrupted the prosecution of
earlier observations, circumstances intervened, on their renewal, which
prevented me from bringing them to a successful conclusion. — Fig. 11.

Plate XXXVI.

Fig. 1. Sertularia ( Plumularia) fascis.

2. Section, comprehending the extremity of a specimen which shows

the arrangement of the parts ; the cells and hydrse.

3. Hydra.

4. Hydra.

5. Section of a stem generating shoots by descent.

6. Section of a stem generating shoots by ascent.

7. The same, farther advanced. The evolution of a hydra, a, followed

in eight days after the section was made.

8. The same, farther advanced, by the evolution of a second hydra, b.

9. The same, still farther advanced, as seen ten days subsequent to the

section.

10. The same, with generations, as viewed by a lens, twelve days after

the section. This is in a horizontal position, the shoots from each
end are vertical. The preceding figures, on a larger scale, represent
the section in a vertical position.

11. Section bearing vesicles. Hydra unfolding, a.

All the preceding, except fig. 1, enlarged.

^ 11. Sertularia argentea — Squirrets Tail. — Plates XXXVII.
XXXVIII. — A complete dissertation on the tribe of Sertularise, should
comprehend many other facts and subjects besides those to be found in

190 ZOOPHYTES.

this treatise ; but ^to do justice to the subject, infinitely surpasses the
abilities of any individual observer, especially one whose resources are
limited. The history of even a single species cannot be effected within
the course of several years. Neither are the finest specimens always ac-
cessible at pleasure, in their various stages, nor in that precise condition
illustrative of their parts and properties. Thence we are compelled too
often to be satisfied with mutilation instead of perfection, and with decay
for vigour : we must submit to many interruptions, both from privation of
our specimens, and from inability to obtain others of the race : or resolve
to accept in the end a mere accumulation of isolated points, without the
means of analysis and combinations. Thus it is, perhaps, that natura-
lists are usually content with founding theories, and detailing descriptions
of dead subjects, from which so little can be gathered in proof of what is
displayed by their animated state. Nevertheless, under multiplied disad-
vantages, if many tread a similar path, and if their industry be not ab-
solutely unrequited, a mass of information is derived from their common
zeal, ultimately profitable to the cause of learning.

I confess myself unable to determine whether the subject of the pre-
sent paragraph be the Sertularia argentea or the Sertularia cupressina of
authors, particularly from entertaining doubts whether the two be truly
different. According to the concentrated matter, always so usefully brought
together by Dr Johnston, I should incline to think it the Cupressina, but
identification fails on resorting to specific detail. Neither is it to be en-
tirely identified with the Argentea. Whence, to shun the perplexity, I
had provisionally designed my own the Sertularia uber, from certain ap-
pearances, leaving future systematic naturalists to reconcile the differences.

Meantime, to avoid embarrassment from precipitate innovation, the
name Argentea is retained.

This Sertularia is the tallest of the zoophytes belonging to the Scotish
seas, — reaching nearly a yard in height. Therefore, in representing it from
Nature, a smaller specimen has to be selected. — PI. XXXVII. It rises
from a root no larger than the scale of a herring, a mere speck in com-
parison to the length of the stem, which is surprisingly slender, and almost
cylindrical throughout, but when in greatest perfection, a little smaller at

SERTULARIA. 191

the origin. On divulsion of a specimen 27 inches high, from a shell, where-
on it had been founded, a scale from the shell, under a line in diameter,
sustaining the root, was separated. Here the stalk scarcely exceeded the
size of a horse's hair, and consisted of a single tube. Four branches, in
alternate pairs, issue from around the stem, nearly in a horizontal direc-
tion where lowest ; and they subdivide dichotomously, or always by cleav-
ing in two. — PI. XXXVIII. fig. 1. These branches are short, contrasted
with the length, for the tallest specimens might be contained in a vessel
of about two inches diameter, whence the branch must be little above one.
The general aspect will be seen from the Plate, XXXVII. Deep annula-
tions indent the stem and branches at irregular intervals, comprehending
from two to ten cells between them. These are more conspicuous in nas-
cent specimens or in decaying adults. Two rows of conical cells, slightly
curved like a horn, clothe the sides of the stem, branches, and their sub-
ordinate parts ; but under considerable discrepancies in form and position.
Those on the stem of younger specimens are sufficiently conspicuous, but
the profusion of branches on the older obscures them. In these, the
latter, they are more in front, in the former, more on the sides ; their true
arrangement alternate. It is to be remarked that the precise relation of
the parts is affected by the increment of zoophytes ; which creates some
embarrassment in an observer comparing his subject with the observations
of others. A notch appears in the orifice of many of the cells of this
species, which is so deep in some, that the higher parts approximate a
spinous formation. — PI. XXXVIII. figs. 2, 3. The annulations of the
stem, which are also a prominent feature in younger specimens, may readily
escape notice in adults, both from the presence of extraneous matter, or
on selecting too short a portion for inspection. Obliteration of the pith
contributes to their exposure.

Considering the ample dimensions of this Sertularia, its hydra, with
20 or 22 muricate tentacula, is very minute. — Fig. 4. To the naked eye
it is a mere speck, pure white, or of greenish hue. The contrast between
these pale animals and the yellow or yellowish-brown of the rest of the
product is great.

The Sertularia argenfea is a zoophyte to be characterized as flexible

192 ZOOPHYTES.

in the genuine sense of the word : the length of the stem is many hun-
dred times its diameter, thence the presence of the liquid element alone
supports it erect, and even then, the higher portion of the tallest, tends to
overbear the rest.

Propagation. — After my earlier observations had been conducted
during several years, their progress was interrupted by an obstacle of too
repeated recurrence, a deficiency of specimens. I found it impossible to
obtain any. During the preceding period, all the vesicles I had seen re-
sembled a vase with a spinous prolongation, very distinct. — Fig. 5. After
a long interval, several luxuriant specimens reached me on April 6, which
were from 8 to 12 inches in height. The branches of some of them were
yielding under a vast profusion of vesicles, resembling minute oranges.
But, unlike the former spinous kind, they were of compound formation,
consisting of a hollow pedestal, surmounted by a sphere about three times
its diameter : and on the whole, bearing much resemblance to the com-
pound vesicle of the Sertularia abietina, above described. Some spinous
vesicles, together with some ampuUate or flask-shaped, were present be-
sides.

A number of the compound vesicles now contained one, two, three,
or four spherical yellow corpuscula, very conspicuous, both in form and
colour, through their diaphanous enclosure. None had more than four,
many were empty, and hardly discernible, from transparence amidst the

water. — Fig. 6.

A vesicle subjected to the microscope, exposed four internal corpus-
cula, one ovoidal, which betrayed symptoms of animation ; the other three
globular and still inert. The former relaxed still more as an ovoid, it be-
gan to move, then shifted its position in the vesicle, where there is always
a considerable vacuity. On directing the microscope to another vesicle,
the contents proved to be much farther advanced : three yellow animals,
all mature, lay parallel to each other within it. One began to move : it
glided slowly upwards to the circular orifice, which opens the summit of the
sphere, from whence, protruding its head as if searching around, it dropped
down among the surrounding element. The second, by a similar course,
followed its precursor, within a minute, and dropped down also. Next,

-' 1

SEETULARIA. 193

the third advancing in like manner at a longer interval lagged in the ori-
fice, as if more doubtful of safety, but at last committed itself as its com-
panions had done, to the water. Now, the sphere remained empty and
quite transparent.

In this way, above twenty planula; forsook their prison during half an
hour's observation. — Fig. 7.

These beings proved very minute, not a third of a line in length, of
beautiful vivid yellow, smooth, and uniform aspect as others ; the body
thick, consistent, and heavy, tapering slightly with obtuse extremities.
They crawled slowly along.

The vesicles continued discharging multitudes of planulse, rendering
that portion of the vessels where they collected yellow from their number.
In five days, at least 1200 had gathered together in the bottom of one
vessel ; and in two days more, at least 2000 in another.

Sertularia uber would not have been an inappropriate characteristic.
None or very few of the planulae ascended the sides of the vessels.
Let us follow the course of metamorphosis.

Planula? issued from the vesicles on April 7. On the 9th, some ap-
]iarently symmetrical the preceding day had now contracted, much after
the fashion of those of the Sertularia fakata. An individual yet exhibit-
ing progression was absolutely spherical.

The period of transformation and subsequent maturity were correctly
defined. Vesicles taken from the specimens above quoted having been set
aside on the 7th of April, planulaj appeared on the 8th. Circular spots
with a spine were seen on the 10th, and on the 17th, hydrse flourished from
the cells of the nascent Sertulariaj. The life of the planula, as such, had
been thus abridged on the third day ; and from the spot closing its exist-
ence, the hydra; had been perfected in other seven. Therefore, within ten
days of the planula escaping from the vesicle, it became a Sertularia.

The spine rising from the spot was yellowish ; the cell enlarging its
summit rather of a long campanulate form ; and the hydra had 15 tenta-

cula.

These characteristics distinguished the young Sertularise.
Compared with the appearance of adults, their form was somewhat
VOL. I. 2 b

194 ZOOPHYTES.

embarrassing. But numerous observations prove the discrepant structure
of the young and the adults, and even between the adults of the same
species of many Sertularise. This is possibly shown under various modi-
fications throughout the whole race. Only a single cell could be disco-
vered resembling the cells of the adult ; but tlws, together with the articu-
lations of the stem of the originating, or of early specimens, established
the identity, although there was no reason to doubt the correctness of
experiments and observations. The cells were very transparent. —
Plate XXXVIII. figs. 8, 9, 10.

The sphere is imperfect, in as far as being then open ; were it per-
manently complete, the orifice would be obstructed.

On different occasions, both simple and compound vesicles have oc-
curred on the same specimen.

A corpusculum, white or yellow, resembling those in the sphere,
sometimes appears on the summit of the pedestal sustaining it.

One or two globular or somewhat elongated corpuscula, probably
planulse, are seen in the ampuUate vesicles.

Besides these, yellow corpuscula have been also observed in the spi-
nous vesicle above mentioned, but under certain irregularities. Of five or
six on a branch, the first contained a large whitish corpusculum, the second
a pale yellow one, the third two more vivid, the fourth had three like
them. The fifth vesicle was crowned by an irregular transparent vessel,
with a yellow corpusculum at the bottom, as if seated on an internal stalk
rising up through the vesicle. Another portion of the lower branch bore
nine spinous vesicles with still greater irregularities. Here a conical ve-
sicle, or a long bladder with contents similar to the yellow globules, of the
wonted sphere, supplanted it.

These varieties or anomalies are of difiicult description to become in-
telligible.

When the great accumulation of above 2000 planulse was verging to
decay, and the whole water emptied on April 18, more than 100 spines
indicating nascent Sertulariaj were exposed on replenishing the vessel.

Vegetation. — The origin and increment of organic bodies, always deeply
interesting to the contemplative, though advancing in strict accordance

SEETULARIA. 195

■with the pre-ordination of nature, may be subject to such disturbance as
perplexes us by apparent anomalies.

Some of these are beyond solution, or they lead to intricate discus-
sion.

For the purpose of investigating the vegetative properties of this Ser-
tularia, a specimen five inches high was sundered on May 26, at a point
of the stem where it seemed tubular and empty.

The upper half, A, Plate XXXVIII. fig. 11, was now inverted, while
the under half, B, remained erect, as in its natural position.

The higher part of A, which before inversion was the lower as fav
as c originally, shot a new generation, c b, upwards, June 13, which
would have descended, had the natural position been preserved. At the
same time, B, fig. 12, retained in its natural position, had generated the
vertical shoot, c b, in the natural direction.

Thus were there two vegetations in opposite directions from the same
point of the stem. They continued advancing nearly at an equal rate ;
but the vigour of B, kept in the natural position, surpassed that of A,
which had been inverted, in the ultimate number of parts ; for the por-
tion c ^ of B no longer than as represented, fig. 12, on June 13, had become,
on December 13, as c b, c a, c d, by new accessions. — Fig. 13.

On June 7, or twelve days after bisection of the stem, a very minute
hydra issued from the lower twig of the natural regeneration, c b, fig. 12,
which animal had been brought to maturity by this interval.

A new generation afterwards issued by descent from B, fig. 12, five
months subsequent to the section, so that, on November 9, it was repro-
ducing from both extremities. — Fig. 14.

One of the lateral shoots of this descending vegetation bore a young
twig or upright stem, a, b, half an inch high, whereon three prominences,
denoting incipient cells, were evident, October 31. These amounted to
six on November 4, four being on one side and three on the other : eight
on November 7, divided as five and three, and on the ninth, there were
ten, divided as six and four. — Fig. 15, enlarged. On November 13, they
amounted to fifteen, divided as eight and seven ; twenty one on the 22d,
divided as eleven and ten ; besides which, a branch with four cells had

196 ZOOPHYTES.

sprung from one side of the stem, on December 10. — Fig. 16. Their number
on both sides of the stem itself, had augmented to twenty-five, on Decem-
ber 23, the lowest now exhibiting a prolongation which formed into a new
cell, displaying a hydra two days later. Another prolongation, as if of
two parts, appeared from the third cell below, on December 7 ; this be-
came trifid on the 9th ; and a hydra flourished from one of its cells on the
15th.— Fig. 17.

The young twig or upright stem, as above, a, b, ultimately remained
nine lines high without farther accessions.

The germinating principle subsists very long dormant, and it is unex-
pectedly demonstrated. Above a year after fig. 12 had been sundered
from fig. 11, a regular shoot with five cells on each side, issued from a
branch situated about the middle of it.

The articulations, generally so indistinct in living adult zoophytes,
were finely exposed by the young specimens. — Figs. 15, 16, 17. Neither
their extent nor their number seemed to be regulated by a uniform prin-
ciple. Most of them comprehended a pair of cells, or a space equivalent
to the site of a pair ; thence, though sometimes comprehending four, it is
questionable whether another, or intermediate articulation, was not incon-
spicuous, simply from being too faint, or whether it was really absent as a
deviation from the natural form and features of the species. The space
intervening between the root and the first cell was indented by eight ar-
ticulations.

The nature of this peculiar feature of zoophytes is not well explained —
whether the articulation is a simple contraction of the parts ; whether it is
a real segment, wherein certain functions may be carried on independent
of the other articulations.

It is exceedingly difficult to account for the generation of hydrae in
these reproductions. The botanist will find a great analogy to the germi-
nation of plants, in their progressive increment generating buds instead of
animals. But where animation is evidently in the developement, it is per-
plexing to conjecture that it may be by the depositation of elementary
atoms, commencing at some certain stage, which the product has at-
taind, as in a, h, — fig. 14 ; or whether it may not be by the evolution of

SERTULARIA. 197

latent germs, subsisting previous to origination of the horizontal thread,
B, /;.

From these and other observations, we may reach the following con-
clusions : —

I. Reproduction from different halves of a bisected stalk may ensue,
at the point of bisection, in opposite directions, being upwards from the
under half, and downwards from the upper half.

II. Hydrae with their cells are generated on both reproductions, if
vigorous ; if feeble there will be none.

III. A hydra has originated and attained maturity in twelve days
from such reproductions ; and one has survived forty days.

IV. An originating portion, having 3 incipient cells on October 31,
had acquired 33 mature cells on December 15, or in 45 days.

V. All the new parts are at first pure white, which, in time, is con-
verted to yellowish-brown.

VI. The arrangement of new parts is by simple divergence in the
same plane : an arrangement altogether different distinguishes the adult
Sertularia.

VII. Original cells are obliterated by new branches germinating in
the line of their axis.

VIII. Vesicles of various configuration are borne by adults, contain-
ing from one to four yellow spherules, developing as planulse.

IX. The planulse discharged by the vesicles have become motionless
in three days ; and the hydrse of nascent Sertularise, generated by their
metamorphosis, have attained maturity in ten days after the planulse issued
from the vesicles.

Plate XXXVII. Sertularia argentea.

Plate XXXVIII. Sertularia argentea.
Fig. 1. Branch.

2. Section of the branch of an adult specimen, comprehending a com-
plete articulation, a h.

198 ZOOPHYTES.

Plate XXXVIII. Sertiilaria argentea.

3. Section of the branch of another specimen, showing the figure and

arrangement of the cells.

4. Hydra.

5. Vesicle.

6. Compound prolific vesicles with spherules.

7. Planulse from the vesicle, a ; one magnified, h.

8. Nascent Sertularia from a planula.

9. Nascent Sertularia farther advanced.

10. Nascent Sertularia, still farther advanced, having two cells and a

hydra.

11. The upper portion, here inverted, of a bisected stalk, which consisted

of A 11, and B 12, united at the point of division. Reproduction,
c, b, as on June 13, from what had been the lower extremity, c,
fig. 11, on bisection May 26.

12. The lower half of the bisected stalk, preserved in the natural erect

position, producing c, b, by upward vegetation, as appearing
June 13.

13. The same reproduction, c, b, fig. 12, with additional regeneration,

c^ a^ — c, d, consisting in whole of three branches, on December IS.
The portion c, B, as seen fig. 12, is here abbreviated.

14. The same section, fig. 13, having generated reproductions from the

lower extremity, B, a new stem, a, b, had arose from one of these,
a lateral filament, which stem had ten cells on November 9.

15. This new stem, a, b, with its ten cells, as appearing November 9, en-

larged.

16. The same, with its accessions, on November 22.

17. The same, with farther accessions, as appearing December 13.

All the figures of this Plate, except figs. 1, 11, 12, 13, 14, are en-
larged.

§ 12. Sertularia antennina. — Plates XXXIX., XL. — How nume-
rous soever the multitude of living hydrae which shall be ultimately borne
by any of the Sertularise, all those whose tenants are provided with muri-
cate tentacula, originate from the planula so often referred to, in as far as
I have been able to trace them. Whether a perfect specimen shall bear

SERTULARIA. 199

few or many, — whether only one, if there be any such, or a thousand, —
whether it be large or small, the common source of the product is that
minute animal. We have seen how this creature, after an indefinite pe-
riod of activity, is arrested, contracts into a circular form, from which a
spine, with a cellular summit, arises, inhabited by a lively hydra. Like-
wise, it appears, how the evolution of subordinate parts is dependent on
the presence of internal pith, gradually diffused by their multiplication
and extension ; that while the specimen survives, the tendency to continual
increase precludes all conjecture of the dimensions to be at last attained.
But these are evidently influenced by age and position.

Life once elicited in the form of the hydra, there seems an incessant
generation of cotemporaries and posterity, until decay or interruption of
the pith announces the presence of disease, or the approach of death, which
infallibly follows.

Already have some prolific products been described, showing their in-
considerable size, though bearing a thousand animated blossoms, together
with their subordinate organs. But others, still smaller, and occupying
still more restricted bounds, sustain ten thousand, nay myriads innume-
rable, literally in such incredible profusion, that the free exercise of their
parts is prevented by their reciprocal interference.

Such are the products I shall proceed to specify. But here the natu-
ralist must not be satisfied with inspecting a single specimen, though,
strange to say, that by multiplying the subjects of observation, he may be
frequently involved in perplexity. Of this an example has fallen to my
lot regarding the present subject : nor do I pretend to elucidate various
points of its history so clearly, that I can hope to satisfy the reader : for
in truth, they are most embarrassing. Therefore, instead of attempting to
reason on the identity of two products, or on their difference, according to
the assertion or the denial of preceding authors, I shall meantime simply
hold them distinct, for the purpose of advancing a few special facts, illus-
trating the general nature of zoophytes.

There is no doubt that the different aspect of the two, which are de-
nominated Sertidaria or Nemertesia Antenuina, and Sertidaria or Nemer-
tesia Ramosa, as well as the detail and arrangement of the parts, is very

200 ZOOPHYTES.

great ; and added to these, the circumstances concomitant on their pro-
pagation. I shall speak very briefly of both exactly as they have occurred
to me.

§ 1. Sertularia antennina — Lobster's Horn* — This product rises
as a single slender stem, ten inches high, profusely clothed -with short, de-
licate twigs, slightly incurving towards it, the whole being of a reddish or
orange colour. The twigs environ the stem in a successive series of sets,
ascending upwards, consisting of four in each, in alternate opposite pairs ;
that is, a twig of the pair opposite to its fellow, and the next pair of the
same kind somewhat higher. The product is of a light feathery character ;
therefore, a group composed as sometimes seen of 100 or 150 specimens,
resembles a rich flexible plume waving gracefully amidst the water. One
feather of the plume is represented Plate XXXIX. fig. 1.

Low cells or denticles seated on the twigs are inhabited by very mi-
nute greenish hydrse, with 14 rather slender muricate tentacula, their
roots apparently connected by a web formed of the expanded disc. These
tentacula clasp suddenly together like some others. The hydra exhibits
no prominent peculiarities. It proves extremely delicate, is seldom found
alive, and it declines speedily. Both the stem and the twigs are distinctly
articulated. If I have entered on no detail regarding this feature of the
skeleton of zoophytes, it is because other authors have devoted so much
attention to the subject. Besides, it is only in the dead and decaying spe-
cimen, not while it is beautiful and luxuriant, full of vigorous animation,
that articulations can be discovered. Probably a few examples may be
afterwards given for general illustration. The articulations of the Sertv-
Inria antennina are distinct ; a spinous prolongation sometimes extends
from the origin of those of the twig. Also, in some of the most perfect

* Ellis, referriog to Ray'as having distiDguished two species, unites them in one. Lin-
nmus seems to view the one only as a variety of the other. Lamarck and M. de Blain-
ville, a very acute naturalist, name the species as 1. Antennularia indivisa; 2. Antennu-
laria ramosa. Lamouroux, under his generic nsxa^ Nemertesia — 1. Antennina; 2. Ka-
raosa ; 3. Janini. Dr Fleming, Antennularia antennina.

SERTULARIA. 201

specimens, a stump, which is apparently an integral portion of the stalk of
the twig interposes on each side between two hydrse. — Plate XXXIX.
fig. 2 ; twig and hydrae, enlarged.

Vegetation. — ^The vegetative faculty of this Sertularia is conspicuously
displayed. A section three inches long having been deposited in a vessel
on September 24, the pith of the middle decayed, but twigs issued from
the sides, both above and below the vacuity ; and from the extremity of
the section also ; hydra; were generated from the twigs, the first of them a
month after the section had been deposited, therefore requiring that inter-
val for maturity.

The upper extremity of an artificial section is likewise prolonged by
reproduction, when new t-wigs originate from it, resembling the slenderest
needles. A stem thus regenerated or prolonged, had 13 series or sets of
such needles. Of these seven bore prolific cells ; but none had above two.
Where progressive increment is advancing, prominences on the stem de-
note incipient twigs, whose gradual growth admits the evolution of cells.
The hydra first displayed is from that cell of the twig nearest the stem of
the Sertularia, and the second hydra from the cell next to the first. There-
fore, the most distant embryo is the least mature.

Propagation. — The stem of this product, which rises singly, is en-
vironed by ovoidal vesicles, with an orifice somewhat heart-shaped, immedi-
ately lower than the convex summit of the vesicle, and almost invariably
opening inwards. The vesicle stands in the axilla formed by the twig
with the stem.— PI. XXXIX. figs. 3, 4.

A single yellow embryo originates here, so large that there seems no
room for more. It is evolved as a planula, surpassing the size of any that
I have seen issuing from a Sertularia, for it is nearly the twelfth of an inch
in length.

Five specimens, crowded with vesicles, were obtained on Novem-
ber 1 9. Sometimes these are in such profusion that the stem seems of un-
usual thickness. Here all were of the same ovate formation, the orifice
inwards, and each vesicle containing a single embryo. Several having
been set apart, planulae of a fine yellow colour, and of the preceding ample
dimensions, appeared in the vessels on November 22. — Figs. 5, 6.
VOL. I. 2 c

202 ZOOPHYTES.

The planulse, from a state of activity, contracted and became motion-
less : being moulded into vivid yellov^' sjiots. These soon exhibited a rising
stalk, whereon projections denoted incipient twigs, from which hydr^
were subsequently generated. I shall insist no farther on the history of
this species of the Sertularia, which has never occurred to me under any
other aspect than as a single red slender stem, with an ovate vesicle in the
axilla of the twig and stem, producing one large yellow planula.

§ 2. Sertularia (Antennularia) ramosa. — This product, which is
either a different species or a distant variety of the preceding, affords
greater scope for observation.

Adult specimens rise four, five, or six inches high, by a short, bare
stem, composed of aggregated tubuli. Numerous boughs and branches
above, diverge at a large angle from their respective principal parts, the
whole thickly clothed with twigs exceeding half an inch in length, and
sometimes bearing 14 or 15 denticles on the upper side. Owing to the
recurvature of the twigs outwards, many specimens present a rich plumose
appearance.

The product is usually of a vivid green colour, sometimes of a yellow-
ish shade ; the lower parts dark, however, or of dingy orange, the higher
and newer tending to dingy yellow. — PI. XL.

The hydrse are greenish, provided with 19 or 20 muricate tentacula.
They are lively creatures, contracting and clasping together suddenly, but
of delicate nature, and difficult to be preserved, which, with the tendency
of whole specimens to decay, should warn the naturalist not to postpone
his scrutiny of the parts, if expecting to find them animated. No peculi-
arities distinguish the hydras, except their identity with the muricate tribe.
The interval between the denticles or cells, is equal to the expansion of
the hydra.— PI. XXXIX. fig. 7.

It has appeared to me that, from the tendency of the growth, the ex-
panded extremities of a luxuriant specimen might be circumscribed by
an elliptical outline. The specimen, Plate XL., which is to be con-
sidered a fine one, rose between four and five inches in height ; its diver-

I

• ^":#

SERTULARIA. 203

gence was six inches by three, computing from the opposite extremities of
the parts.

The stem of the Ramosa is generally very short. It consists of tubuli,
of which at least an hundred are aggregated when it is a line in diameter.
The central tubuli are almost black ; those towards the circumference are
replete with the pith. A transverse section of the stem exposes a kind of
porosity resembling what may be discovered in the thin slices of certain
species of wood, under the microscope. But the pores are neither of regu-
lar figure individually, nor in regular arrangement. — PI. XXXIX. fig. 8.
This fasciculated structure, which is very obvious below, disappears above
and there the different stalks of the parts resolve into a simple tube.

The stem of several specimens of the preceding red species, the An-
tennina indivisa, which were some inches high, but of smaller diameter,
proved a simple thick-sided tube. The aggregate tubuli of the Ramosa,
however, are of perfect and independent organization, such as renders each
in vigour capable of regenerating new parts.

On forcible divulsion, the root of this product, i\xe Ramosa, separates
as a flat mossy tuft, about half an inch in diameter : but the presence of
what is either a mass of foreign matter, or a multitude of short radicles, ob-
scures its true formation in the adult state. It is sufficiently evident in
an early stage.

Vegetation. — The regenerative faculty seems more vigorous in this
Sertularia than in any of the race, — to which we may possibly ascribe the
great embarrassment of observers in determining its distinctive features.
Such a property, nevertheless, renders it a favourable subject for physiolo-
gical enquiries.

A group of the green Sertularia ramosa, most narrowly resembles a
plantation of pollarded trees in miniature. Dark, aged stems, sustain
fine green vigorous reproductions above, of all dimensions and in every
stage.

If the upper portion of an adult be sundered, shoots issue from the
tubuli of the stump remaining behind, both from those towards the centre
and from others towards the circumference. Great analogy here appears
to the vegetable creation. Subsistence of the pith is indispensable to the

204 ZOOPHYTES.

life of the product. Its regular decay commences in the subordinate parts,
at the point farthest from the principal part. When beginning at the
extremity, decay descends gradually from the newest, slenderest, and weak-
est parts towards the stronger and older. But its progress may be ar-
rested, and then vigorous regeneration ensues from the point of interrup-
tion. Next, the transparent vacant tubular portion above, which the pith
had occupied, drops off, and a new shoot rising from the stalk thus muti-
lated, is clothed in time, like its precursor, with twigs, bearing cells and
hydr£e. Intermediate interruptions of the pith from decay, throughout
the stem and branches, produce similar consequences. Besides these,
many sproutings vegetate from the lower parts of \igorous branches, where
none were previously seen. All this contributes to the luxuriance of the
product, and thus the various parts in various progress, and of varied hue,
tend to render these Sertularise an accurate resemblance of a pollarded
plantation.

From the extraordinary effects of decay and reproduction, I have
seen a well-marked specimen, so completely changed in the course of a
few months, that unless it had been kept under constant observation, no-
thing could have identified it. This specimen consisted of eight or ten
boughs and branches originally. In the course of ten weeks all the larger
limbs were reduced to half their pristine length or less, by progressive
natural mutilation. Meantime, supervening reproduction had generated
above thirty new shoots from different parts, — some of them an inch
long ; whence, by privation and accession, the greatest alteration appeared
throughout.

In one instance, an entire stem vegetated from the lower end of a
section which had been taken from the summit of a branch.

Such an extraordinary diversity of aspect, not only in different speci-
mens, but in the same specimen, merely resulting from time and circum-
stances, renders it difficult to assume such indelible characters as shall dis-
tinguish many zoophytes.

Both the red and the green Sertularia antennina occurring to me
have been always founded on shells.

Propagation. — In the determination of genera, species, or varieties,

SERTULARIA. 205

the peculiar mode whereby the race is carried on, may prove of great as-
sistance. Little difficulty is experienced here, among the higher depart-
ments of zoology, but on descending to the lower, the subject becomes
more obscure.

In considering the two products before us, we find the red Serftdarid
antennina rising by a single stem, clothed with innumerable slender twigs,
issuing immediately from it, that it bears ovate vesicles set in the axilla
formed by the twigs with the stem, each producing a single very large
planula : and that the entire specimen may be contained in a cylinder ten
inches high, and of eight lines in diameter.

On the other hand, contrasting the green Sertularia (antennina)
ramosa, we find the adult always consisting of a number of subordinate
parts ; first boughs originating from the stem, then branches profusely
clothed like the other with twigs, but never occurring, to me at least,
nearly of equal height, nor bearing similar vesicles exclusively on the sub-
ordinate parts.

In very luxuriant specimens of the latter, that is the green, there are
interspersed among the various parts, long slender twigs or branches, bor-
dered on each side by the finest, most delicate hairs with cells and hydrse ;
and bearing long ampullate vesicles. — PI. XXXVIII. fig. 9.

The last are frequently in vast profusion ; sometimes pure white, some-
times reddish, according to the nature of their contents. These vesicles
do not in the least resemble the ovate form just described. But consider-
able difference appears in the length and obliquity of the neck, as well as
in the colour, of those of different specimens.

Such are the vesicles usually occurring on the Nemertesia or Sertularia
ramosa of Plate XL. But to comprehend the subject sufficiently, would
almost require ocular inspection of the original, for description is not to be
conveyed in words.

On the 29th of October, the contents of some prolific vesicles, which
had been set apart two days preceding, were found in various progressive
stages, and presenting obvious diversity of appearance. Minute spherules
or spherical triangular prisms were among them.

Life became evident in the contents of several vesicles now subjected

206 ZOOPHYTES.

to the microscope. The spherules were gradually developing in a pris-
matic foi-m ; and one, as if elongating to its proper figure, deliberately as-
cending the side of the flask, issued head foremost from the mouth. But
it first hesitated there a moment, then dropped down through the water,
wherein its fall was sensibly retarded, as if by an invisible thread, and on
reaching the bottom, it glided swiftly away. In a few minutes, another
rising within the same flask, forsook it under similar circumstances : and
then a third followed after a short interval— PI. XXXVIII. fig. 10, a, b.

The planula thus produced is very minute, not exceeding the sixth
part of the size of the single yellow planula from the ovate vesicle of the
red Sertularia — by which I mean in the quantum of matter. It is white
to the eye or grey in the microscope, the head obtusely rounded and about
twice the diameter of the opposite extremity, which is obtuse also. —
Fig. 11.

The most prolific vesicles of fig. 10, contained about twelve spherules
indistinctly disposed in a double row. — Fig 12. But the contents of
others amounted to 24, 26, or even 30, imder similar arrangement.—
Fig, 13. A branch, scarcely half an inch long, bore fifteen prolific vesi-
cles, besides a sixteenth empty and transparent. No definite forms could
be discovered in the contents of some ; others contained irregular sphe-
rules, which, in several, were evolving into triangular prisms, denoting
progress towards perfect planulse, escaping from the rest. Fifteen em-
bryo planulse filled a vesicle, all losing their spherical form, which, along
with the contents, also discharged from another vesicle, during observa-
tion protracted an hour and a half, constituted a brood of 30 mature and
perfect subjects in whole. These animals did not surpass the third or
fourth of a line in length. No difference from the preceding which had
escaped from the vesicle just referred to, could be recognised except in
colour, these last being faint pink, while the preceding planulse were
white. They betrayed no activity, unless in quitting the vesicles, which,
correctly or not, was ascribed to the coldness of the day. Now the power
of a retaining filament was very evident. Everything would have sanc-
tioned the association of these creatures with the Planaria proper, in figure,
motion, and in habits.

SERTULAEIA. 207

As this insignificant branch bore fifteen vesicles, wherein from 15 to
20 planulse belonging to each could be enumerated, its fruits amounted to
between 200 and 800 in whole.

None of the animals escaped from fig. 13, during observation, though
all relaxed into ovoids and prisms, and altered their reciprocal position.

The perfect transparence of the vesicle, exposes whatever succeeds
within as the contents are gradually discharged. — Fig. 14.

Specimens of what might be denominated the Nemertesia ramosa, oc-
cur, with a short stem, boughs, and branches, set at a large angle, together
with the prolonged, slender, and very delicate twigs above described, as
issuing from parts of the latter. Two such specimens had a ruddy tinge
towards the root, while of a dull yellow colour above, where the pith had
decayed. The articulations were distinctly seen. Living hydrae occupied
the portions entire.

A profusion of ovoidal vesicles, with a heart-shaped orifice, were set
in the axillae formed by the parts of these specimens, each containing a
corpusculum, which came forth as a pale yellowish planula, quite the
sixteenth of aia inch long. It swam supine as the Planaria, and it might
have been identified with the planula, coming from the ovate vesicle of
the former species, the Serttdaria antennina, rising by a single red stalk.
Similar facts have recurred at different times, when many planulse were
produced.

Besides such ovoidal vesicles, the delicate, slender, plumose twigs
bore transparent empty flasks.

Thus the same specimens bore ovoidal and ampuUate vesicles.
But greater perplexities have occurred from other specimens, bearing
three distinct vesicles on their different parts, stem, boughs, and branches.
Such specimens, green and branched, which I concluded the Ramosa, were
obtained in October. The vesicles consisted oi first, the owid with a late-
ral orifice as described, which never contains above a single planula, and
remains empty and transparent on its departure. Second, a cornide vesicle,
or one like an inverted horn, the larger diameter outwards, with the ex-
tremity a circular mouth : the vesicle set round the stem, after the arrange-
ment of the ovoidal vesicles, being also of about the same capacity. —

208 ZOOPHYTES.

PI. XXXVIII. fig. 16. Third, Long flask-shape or ampullate vesicles
sustained on the twigs issuing from the branches, which vesicles were not
half as large as the horns. Yellow planulse, half a line long, were pro-
duced from these cornute vesicles, exhibiting nothing remarkable. —
Figs. 16, 17. They proved rather languid, owing to the chill of October.
Some remained entire ; others were contracting in two days ; and soon
after several decomposed into granular particles, as incident to the Plana-
riae. Then, the Animalcula infusoria are speedily generated.

In regard to the cornute vesicle, that or one narrowly resembling it,
is represented in Lamouroxuv' s work on the Flexible Corallines, as distin-
guishing the Nemertesia Janini, the second species of his genus Nemerteaia.
Almost the whole descriptions of that Treatise seem to have been derived
from dried specimens, and possibly from very small fragments of them ;
whereas, in those presenting such varieties, or anomalies, as two or three
different shaped vesicles appearing on the same specimens, all its parts
must be brought into view.

I shall merely allude to another vesicle which I was induced to as-
cribe to the Sertularia or Nemertesia ramosa, of this paragraph, without
having had leisure and opportunity to confirm the fact. Thence, on future
investigation, it may be found to belong to some cognate. In my specimens,
numerous vesicles resembling a vase with a serrate orifice, were crowded
together on one side of the stalk, not being disposed around it like the
ovate vesicle of the lobster's horn. But this contained a single large pla-
nula, with a ruddy tinge, about the sixteenth of an inch in length. Above
fifty were produced on September 13, during the course of a single obser-
vation. From some unknown cause, a ropy scum formed on the surface
of the water in the vessel containing them, which being removed, by re-
plenishment to overflowing, exposed slender spines with an enlarged sum-
mit rising from stellate roots. In 24 hours, that is on the 18th of Sep-
tember, a lateral bud, beside the enlargement, displayed a pale green hydra
with 16 muricate tentacula. The root had now partitioned into ten or
twelve heavy divisions, bounded by a narrow transparent margin. The
hydra flourished before the spine had rose three lines. But neither did it,
or any others generated on the same occasion, survive above three days. —

SERTULARIA. 209

Plate XXXIX. fig. 18., Serrate vesicles, producing a yellow planula.
Fig. 19., Nascent Sertularia from the planula.

Amidst considerable embarrassment on the subject, the preceding,
combined with other observations, seem to warrant the following conclu-
sions : —

I. That there are two distinct species of the Sertularia antennina of
the older authors.

II. That the Sertularia antennina of the Linntean system, the modern
Antennularia indivisa, appears as a single ruddy stalk, ten inches high,
begirt by slender verticillate twigs, and bearing axillary ovate vesicles,
each containing a single yellow planula.

III. That the Sertularia antennina of the same system comprehends
also a greenish shrub, diverging into boughs and branches, clothed with
twigs : likewise with slender, prolonged, plumose vegetations sometimes
interspersed, whereon, besides hydra?, are borne long, ampullate, axillary
vesicles, each containing many planulse.

IV. That three vesicles, all different from each other in form, may
appear on the latter, the Sertularia ( Nemertesia) ramosa.

V. That vigorous reproductive energies reside in the Ramosa, which
are readily and frequently exhibited : while similar energies are feeble and
rare in the Antennina indivisa or Lobster's Horn.

Plate XXXIX.

Fig. 1. Sertularia antennina (Antennina indivisa — Nemertesia Antennina),
Lobster's Horn.

2. Twig with hydrse.

3. Section of a stalk with a vesicle.

4. Section of a stalk with vesicles.

5. Planulse from the vesicle.

6. The same enlarged.

7. Sertularia (Nemertesia) ramosa. Twig with hydrse.

8. Section of the stem.

9. Plumose prolonged twig, with hydrse and axillary vesicles, enlarged.
VOL. I. 2d

210 ZOOPHYTES.

Plate XXXIX.

10. Vesicles crowded along the rib of a twig. Planulse escaping from

the vesicle, a, b.

11. Planula free.

12. Prolific vesicle with a double row of spherules.

13. Prolific vesicle, with the contents changing their shape and position.

14. Prolific vesicle, with the contents, originally spherules, relaxing into

planulse, one of which is advancing to the orifice.

15. Section of a stem with cornute vesicles.

16. Planulse from the cornute vesicles.

17. Planulffi from cornute vesicles.

18. Section of a stalk bearing prolific vesicles, with a serrate margin.

19. Nascent Sertularia, from the planula.

All the subjects of this Plate, unless fig. 1. and fig. 5, are enlarged.

Plate XL. Sertularia ( Nemertesia) ramosa.

CAMPANULARIA. 211

CHAPTER T.

CAMPANULARIA.

It is less from conviction of its use or necessity than from the expe-
diency of compliance with modern fashion, that the present title is applied
to the brief chapter introduced here.

Besides, I cannot but judge it questionable whether the genus Cam-
panularia should be retained in the St/stema, at least as now constituted.

If new genera are to be framed from the partial dismemberment of
those already established, and augmented by the incorporation of other
species, we expect, in the first place, that they shall be founded on in-
delible characters ; and, in the second, that an incongruous association of
the component parts of these species shall be avoided.

Naturalists, perhaps too earnest in quest of ostensible distinctions to
warrant a change of nomenclature, or to facilitate what they presume are
better arrangements, have precipitately adopted as permanent features,
what time and study will prove no more than transient.

An example may be probably found in this paragraph. But it is not
for that reason the subject is introduced. On the contrary, as we are still
engaged with the hydraoid arborescent zoophytes, it is for farther illustra-
tion of their nature. We also find an opportunity for resuming a view of
some remote connection between the origin of one animal and the exis-
tence of another, without being able to trace any reciprocity either in form
or in habits, between them.

While shortly treating of the Tubularia ramosa, in another place,
something was said of the mysterious appearance of certain species of Me-
dusae, and the perplexities wherein they involved the observer. Were

212 ZOOPHYTES.

similar instances recorded, our embarassments might be relieved : for more
frequent, easier, and stricter investigation being admitted, doubtless such
a train of discovery, and thence the solution of what are to us the most
abstruse problems, would follow.

Thus let us patiently persist in our enquiries after the purposes of
Nature.

§ 1. Sertularia (Campanularia) dichotoma. — Sea Thread Coral-
line.— Plate XLI. — The Sea Thread Coralline is one of the most delicate,
elegant, and interesting, among the numerous race of arborescent zoo-
phytes, which none of the names hitherto bestowed on it are in the least
calculated to express. According to Pallas, it rises a foot in height, whence
the species is distinguished by him as Sertularia longissiina. But none of
my specimens have exceeded nine inches. Much allowance must be made
for the situation of all such products : nor, on comparing certain apparent
discrepancies among those occumng to me, do I think that I have either
had the finer specimens, in their greatest luxuriance, or that I am yet en-
abled to ascertain what are the existing varieties.

This zoophyte rises erect by a dark brown tubular stem, extremely
slender, being truly no thicker than a silken thread, but tough and elastic.
The whole skeleton is waved — the stem less sensibly, owing to its greater
length ; the branches, by about 30 or 40 of which it is environed, are more
decidedly so. Here the reader may preserve in recollection, that such
products lose much of their original character, simply by increment. Hence,
on ascending to the nascent state, it is impracticable to determine what
the early zoophyte shall be, unless having seen the parent. Twigs rise
from the convexities of the branches of this Sertularia, which, instead of
termination by a tubular or cylindrical extremity, dilate as a bell of incon-
ceivable transparence and tenuity. A specimen, eight or nine inches high,
might be covered by a hollow cone, four inches wide towards the base. —
PI. XLI. fig. 1.

The skeleton is- occupied, as usual, by an internal pith, terminating
at the origin of the bell by the evolution of the hydra ; for wherever the

CAMPANULARIA. 213

inorganic parts were suflSciently diaphanous, a hydra has always appeared
to be connected with the pith. Here the animal is contained entirely
within its transparent bell, which is wide and capacious, in proportion to
the dimensions of the body, and from hence it ascends to display from 24
to 30 deeply muricate tentacula over the edge. The neck and head are
very long, within which the stomach is seen descending quite to the bot-
tom, and the mouth appears above, generally contracted, in a hemisphe-
rical form ; but sometimes dilated like a cup. This is a very timid animal.
It retreats suddenly within, from complete expansion, and crouches down
to the bottom, where it is clearly exposed in its diaphanous habitation. —
Figs. 2, 3.

The branches of many specimens are deeply indented by from five to
nine whirls, at the forking of the limbs from each other : and similar
whirls indent the twig immediately under each bell. But numbers
are not so distinguished ; they bear no such whirling ; whence I am dis-
posed to infer, that there are species or varieties with which I am not yet
familiar. These whirls do not constitute a spiral ; nor does any part of
the product relax as a spring or screw, which might be inferred from the
descriptions of naturalists. I have never witnessed anything of the kind
among zoophytes. All that I have seen are either simply flexible or they
are rigid.

This coralline is of great luxuriance. Before a young specimen had
rose an inch, it bore 56 hydrae. One, nine inches high, bears above 1200.
All are of light grey colour. The product is white in its origin or earlier
stages ; smaller subjects remain so. Their formation is by divergence in
the same plane ; but the formation of adults is by branches, springing from
around the stem, and shortening as higher above the root.

The decaying extremities of adults are sometimes regenerated, when
new twigs together with the hydrse are perfectly white. Now the ex-
treme tenuity of the bell completely exposes the progress of the included
embryo. When matured here, as well as when recovered in perfection
from the sea, the animal proves of delicate nature, surviving but a short
time.

Soon after its decay, the bell falls also, which proves the inconsis-

214 ZOOPHYTES.

tency of assuming this part of the organization as a permanent charac-
teristic.

Vegetation. — As already alluded to in the history of other Sertularia,
the natural configuration of this species is disturbed by a vigorous reno-
vating extremity coming in contact with some solid substance, such as
the side of the vessel containing it. Now, there is no room allowing
the alternate origin of branches from the circumference of the stem,
during ascent, if that be the mode of its growth. All issue from the out-
side of the stem, which is climbing in adhesion. From each side of a
stem of the same diminutive proportions as the adhering shoot, a branch is
generated. Such branches appear as mere spines in this adhering vegeta-
tion. The higher extremity of the vegetation does not itself flourish ; but
a little lower, a spine shoots out, of which the summit soon enlarges with
a bell and hydra. At this juncture, the extremity of the vegetation hav-
ing advanced somewhat higher still, without flourish, a new spine, a little
lower than the top shoots out, M'hich speedily enlarges above with a bell,
wherein a second hydra is developed. Thus the second hydra is midway
between the first and the ascending extremity of the vegetation. Next,
while the two are flourishing, a spine shoots out of the twig, bearing the
first or lower hydra, forking with it and flourishing likewise ; meantime
the same succeeds in relation to the second or higher hydra — the stem
in adhesion still continuing its ascent. By this process the lateral vege-
tation, by means of branches, enlarges the expansion of the new produc-
tion generated of the adhering shoot ; but it is not to the same extent as
the vertical vegetation.

The progress of this Sertularia, adhering thus by a shoot in contact,
is sometimes rapid. A new hydra has been brought to maturity in 48
hours, from a point where a spine was previously imperceptible.

The originating stem ascending in this manner advances a line in 30
hours, or about an inch in eight days.

The extremity of such a regeneration as now described having reach-
ed the side of a vessel, it ascended by adhesion, and dispersed lateral
branches, also in adhesion during its ascent. In about a month 62 spines,
bells, and hydrse were generated, whereof 30 sprung from the stem, the

CAMPANULARIA. 215

rest from the branches. All were entirely new. The reproduction had
rose 30 lines, yet its energies were not exhausted, as shewn by farther ad-
vances.

Here, after ten spines had been generated, an eleventh shot from the
stem on September 20, — next day the hydra was about to flourish. A
needle had then forked off it, and hydrse from both were displayed on the
22d. The hydra from the needle decayed in 24 hours. That from the
spine subsisted three or four days. The twelfth hydra, mature also on
the 22d, decayed in three or four days ; so that the animals originating
from the reproduction had little permanence.

Propagation. — From anything yet said on this subject, it seems ques-
tionable whether the precise mode whereby the Sertularia dichotoma per-
petuates its race is sufficiently explicit. Perhaps it may be found to bear
more than one kind of vesicle.

On rare occasions I have seen numerous ovate vesicles borne by
this Sertularia among the bells containing living hydrae, and in the propor-
tion of about one to thirty of the latter. Their position is no farther
l)eculiar, than in being seated on the upper side of the branches ; and they
are generally empty, as if having fulfilled their purpose. When present,
their numbers on a branch sometimes amount to eight or ten.

These vesicles are of a grey or a greenish colour. When prolific, they
contain twelve or more dull grey corpuscula, each with a dark central
nucleus, and all as if compressed together. — PI. XLI. figs. 4, 6. They are
void of any resemblance to the corpusculum in the vesicles described of
the other Sertularias, developing from a globular form, and escaping as an
active planula from the orifice of the vesicle.

When the contents of that now in question approach maturity, some
internal motion is betrayed towards the summit of the vesicle ; the tijjs
of the tentacula of an included animal protrude ; then stretching farther,
they clasp convulsively, as if to free the body within. After much appa-
rent exertion this is gradually accomplished, but instead of the accustomed
planula, we next behold a creature allied to the Medusa, which has
escaped from its prison.

At first I could scarcely credit the truth of so unusual an occurrence ;

216 ZOOPHYTES.

one presenting such a remarkable deviation from the nature of the pro-
geny discharged by the vesicles of the various Sertularian tribes. But I
was unable to recognise any error, either in the previous existence of the
Medusa within the vesicle, or in its liberatiou from it. I have seen the
same repeated several times, though at distant intervals ; the last occasion
being in July 1840, when a number of vesicles happened to be under ob-
servation, all of the same character.

One Medusa at the very bottom of a vesicle had there developed
prematurely. It was distinctly observed clasping the tentacula below,
while its escape from above was precluded by the intervention of others

still immature.

The vesicles in progress, fall and empty, are represented figs. 4, 5, 6, 7.

When originally observing this animal, before ascertaining its origin,
I had bestowed the name Tintinnabulim on it, from its resemblance to a
hand-bell; and I believe that its general aspect will justify such an appellation.
It is of some importance to find familiar objects for illustrating those un-
known. The body resembles a minute watch-glass, half a line in diame-
ter, bordered by a pendent marginal fringe of about 23 muricate tentacu-
lar organs issuing from an enlarged root, and nearly as long as the diame-
ter of the disc. A central prolongation below corresponds to the proboscis
of the Medusa, which is thus seen while the animal suspends itself in
equilibrio among the water. When reversed, it appears like a crest on a
convex surface. Four lines with enlarged extremities, diverge from the
base of the proboscis ; likewise four lines at right angles seem present

above. — Figs. 8, 9.

The animal is whitish or almost transparent It swims by jerks, or
bounds like the various species of Medusa?, from collapse of the body,
perhaps aided by the tentacular organs. It pursues all directions, rising,
falling, or remaining stationary in equilibrio. Like a group of the Medui-a
bifida, these creatures narrowly resemble a flock of minute birds wending
their course through the expanse of the firmament.

This animal courts the light.

In the progress of evolution they rise upwards in the vesicle, and in
as far as I could discover, the tentacular organs protrude first, in which

CAMPANULARIA. 217

if I be right, a correspondence appears between their developemeut and
that of the Medusa ocilia. But I should desire an opportunity of repeat-
ing this observation. Considerable exertion seems requisite for liberation,
and many perish in partial protrusion. All having quitted the vesicle, an
opaque columnar substance, with an enlarged summit, remains.

The life of these creatures is transient; they disappear insensibly,
or they fall to the bottom of their vessel, where they die. The longest
period I have been able to follow them was nine days, when they still rose
a little amidst the water.

During March and some subsequent months of summer, numerous co-
lonies of the T'mtinnahulum have been produced in different years from such
vesicles as above described. No other animals have ever issued from them.

The figures given by Ellis, Plate xxxviii. fig. 3. B. and by a later
author, Mr Lister, in the Philosophical Transactions, Vol. cxxiv. PI. x.
as of young hydrse escaping from the vesicles of the Sertidaria dichotoma,
are quite unintelligible by me. No doubt it is possible, however impro-
bable, that the ovum in the vesicle of a Sertularia may relax as a planula ;
that a spine may originate from the planula if retained long enough, and
then a hydra. But all this is adverse to the ordinary course of nature.

If the accounts of the two authors now named could be reconciled
to any facts that have occurred to me, I should conclude that it is the
Tintinnabidum they have seen escaping from the vesicle of the Sertularia
dichotoma.

A series of accurate observations on multiplied specimens has still
to determine the real distinctions of the Campanularia dichotoma, the
C. genicidata and gelatinosa.

Plate XLI. Fig. 1. Sertularia dichotoina.

2. Hydra and bell, front.

3. Hydra and bell, profile.

4. Portion of a branch with a hydra and vesicles, showing

their relative proportions.

5. Portion of a branch with immature hydrse still in their cells,

and a hydra in retreat, a.
VOL. I. 2 E

218 ZOOPHYTES.

Plate XLI. Fig. 6. Prolific vesicle. Here the contents, as in others, are in

a double row.

7. Tintinnabulum or Medusa quitting the orifice of the vesicle.

8. Tintinnabulum at large, reversed.

9. Tintinnabulum in plane.

, All the figures of this plate, except the first, are enlarged.

§ 2. Sertularia (Campanularia) verticillata. — Plate XII.
Figs. 1-8. — Although the young of this product be sufficiently numerous
and easy to be obtained, nor of difficult preservation, its rarity as an
adult, in any places I have resorted to, forbid conjectures regarding both
the dimensions and the luxuriance which it may ultimately reach.

For many years I "was induced to consider the species as consisting of
no more than a single hydra in its bell, sustained by a stem ; that in this
simple form it originated, flourished, and decayed. As such, it should
have attracted the notice of preceding naturalists, especially from its size,
being one of the largest camj^anulate hydrse in the Scotish Seas.

In a better stage it has occurred to me as an erect stem, with one or
two subordinate branches, but nothing more. However, others have had
it in greater luxuriance. — PI. XII. fig. 1.

This zoophyte rises above two inches high by a short stem, composed
of aggregated tubuli, and with an obtuse summit. Branches originate at
a large angle from the stem, bearing campanulate twigs and hydrse, in
sets of four, five, or six. The twig is faintly whirled, sometimes so in-
distinctly as to be scarcely perceptible ; and the bell is of excessive tenuity.
This is in the form of what is called a Chinese bell, having a plain or ser-
rate lip, for both are undoubtedly seen, without denoting a species obvi-
ously distinct. It may constitute a variety.

The hydra rises within the bell to display above 30 muricate tenta-
cula. — Fig. 2. But when fully extended, these lose their muricate aspect
under the microscope, then resembling articulated organs with several
very short obtuse spinous processes from the origin of each articulation.
The animal seems to be capable of exercising some slight influence over
the twig.

The inorganic parts are of faint greenish-yellow colour ; the hydra of

k

t ■!>':

f.'

I

I

./

CAMPANULARIA. 219

a fine ruddy hue — whicli seems partly dependent on the food or the
season. Those highest coloured are always single specimens, that is, con-
sisting of a single bell and hydra, when their numerous long tentacula re-
curving over the Up might be supposed in alternate arrangement, or al-
most a double row, which is somewhat the character of the preceding
subject. In this state the zoophyte is like a beautiful flower.

The central pith of the twig seems susceptible of contraction and ex-
tension by the rise and retreat of the hydra, if it be not an optical illusion.
Perhaps something analogous to muscular powers may belong to such
minute products.

This zoophyte is generally meagre ; but it is embellished by the
spreading of the hydra over its delicate bell. In most of the Sertularian
tribes, the sheath, denticle, or cell, constituting an inorganic part for re-
ception of the hydra, remains permanent, but here the bell always falls on
the decay of its tenant. The two are mutually dependent on each other.
There is a striking contrast between fig. 1, a specimen in vigour, and one
where only a number of vacant twigs remain. — Fig. 8.

That specimen was embellished by about 100 hydras with their trans-
parent bells, 70 being on the main stem, and 30 on the branch. All were
in the highest vigour, some in ample developement, displaying their lively
action, others rising cautiously to spread over the lip of their dwelling, or
clasping the tentacula, and suddenly crouching down in retreat below.
But their decay was rapid. In 48 hours from the first enumeration when
obtained, the whole were reduced to 36, distributed in equal proportion
on the stem and on the branch. In another day only 6 remained ; on that
which followed no more than one. Most of the bells had also fallen.

Thus had an hundred living beings perished on the fourth day after
visrorous animation.

Meantime from the same reproductive energies residing in other
species, many of the vacant twigs which had previously borne animals were
extending, and speedy regeneration ensued. A long clavate enlarge-
ment of the growing twig unfolded as a new hydra with its bell.

Thence it is evident that decay of the bell should be concomitant
on the decay of the hydra. It is part of the arrangements of Nature.

220 ZOOPHYTES.

In this manner five hydrae were generated on the main stem between
May 2 and 6, and seven on the branch between May 2 and 7. But the
branch becoming limber, proved in total decay on May 29.

After the stem had been sundered near the root, a shoot rose from
the remaining stump, which bore a hydra in eight days.

A twig from the sundered portion having come in contact with the
glass vessel containing it, extended and generated subordinate parts.
Thirteen hydrae were generated from them in eighteen days, and one ad-
ditional in the course of a month. The period of their subsistence was
usually two or three days.

Three shoots had descended from the extremity of another sundered
stem, each extending half an inch in nine days, and then bearing a hydra.
Their length having doubled in a week, one bore two, and each of the
others three hydrae, all vigorous.

Thus there are generations both by ascent and by descent, because a
prolific shoot rose from the preceding stump ; and prolific shoots descended
from the lower end of the section.

These facts may be compared with what is said of the Sertularia
fascis, and of others.

Considering the position allotted to this product by modern systema-
tists, the mode of its propagation merits notice.

It is seen that the preceding species of the Campanularia or Sertularia,
the dichotoma, discharges a number of minute Medusae. The present species
bears a prolific ovoidal vesicle, exactly resembling a Florence oil flask,
with a long tubular neck and circular orifice. Vesicles of this kind, in-
terspersed irregularly with the twigs on the stem, have occurred in May
and in July. — Fig. 3. Instead of Medusae, they contain three or four
planulae, which are very conspicuous within ; figs. 4, 5, and escape when
mature, as white, fleshy, and a little flattened, fig. 6.

The rarity of the product has opposed my further investigation of the
history of these creatures. If they truly belong to the same genus as the
Sertularia dichotoma, it would be strange to find one of them propagating
through the medium of a Medusa, and the other through that of a planula.

Specimens of the Verticillata appear of finest quality in their earliest

CAMPANULARIA. ' 221

stage, when dispersed as single hydrse, or when the zoophyte consists of
very few. They are numerously scattered over shells, founded on Ascidice,
or rooted on other products ; these are always larger and their colour more
vivid.

From their frequency in the single state, together with the rarity of
adult and luxuriant specimens, the naturalist receives a useful warning
against presuming on the ultimate aspect of any zoophyte. Likewise, on
finding nothing but the twigs or pedicles of fallen bells, interspersed with ■
vesicles, as in fig. 3, which very shortly follow them, he will perhaps deem
the Campanularian form too equivocal a characteristic of the species.

Plate XII. Fig. 1. Sertularia (CampanulariaJ verticillata.

2. Hydra displayed from its bell.

3. Vesicles interspersed with twigs of fallen bells.

4. Prolific vesicle.

5. Prolific vesicle.

6. Planula.

7. Bell with a serrate lip.

8. Regenerated portion, having lost the hydrse and bells.

All the figures of this subject, except the first, are enlarged.

§ 3. Sertularia (Campanularia) dumosa. — Pl. XXVI. Figs. 22-25.
— The narrow resemblance of this product to common furze, when viewed
by the naked eye, had induced me to name it Sertularia Ulejo, before
having been aware of its distinction otherwise.

Though now enrolled by some authors with the Campanularice, its
structure is very different from that of the two preceding species.

It appears, like many, under some modification ; but it does not seem
to grow in much luxuriance wherever I have sought it.

The dumosa rises two or three inches, by a short stem, subdivided
meagrely into boughs and branches, with a slight incurvature. — PI. XXVI.
fig. 22. Long inverted, transparent, conical cells, not bells, issue from
around the boughs and branches, their opposite orifices being about a line
asunder. They seem disposed in pairs, that is, one opposite to the other,

222 ZOOPHYTES.

in some specimens, but less definitely so in others. The cell is sessile or
without the intervention of any pedicle or twig connecting it to the stalk.
—Fig. 23.

The hydra is well exposed through the sides of its transparent cell,
when the body is discovered as originating immediately from the internal
pith of the stem, or branch whereon the cell is sustained. It is of much
smaller diameter than the cell, tapering regularly downwards, and ascends
• to display from eight to fourteen deeply muricate tentacula. This great
irregularity of the number occurs on the same specimen. — Fig. 24. There
is likewise a difference in the form of the cells, from which those of the
same specimen are not exempt. But it is most conspicuous on the com-
parison of several. — Fig. 25. The lip of the bell is even. The general
asjject of the adult hydra is greenish-yellow. Vivid grass-green distin-
guishes the hydra itself and all later accessions. The cells are of the faint-
est yellow, older formations are brown.

Probably the hydra is regenerated. In its progressive advances it is
seen in a long clavate shape, through the side of the cell, with some en-
largement of the pith at the point whence it originates.

Short shoots frequently issue from each extremity of a section, which,
if vigorous, bear hydraj, but if feeble, they extend irregularly and prove
abortive. — Fig. 24, a.

It seems a general law with the greater part of the Sertularian tribes,
that hydrae shall develope from all vigorous vegetation conveying the pith.
But nothing animated comes of what is feeble and irregular.

Nevertheless, the precise order of the new subsidiary parts is dis-
turbed on the contact of such vigorous vegetation with solid substances.
A section of this Sertularia had generated a shoot an inch long, which in
seven weeks had run in adhesion along the bottom and up the side of a
vessel. Three cells with hydraj sprung from the horizontal portion on the
bottom ; and one, which was abortive, from that on the side. These four
would have stood in jjairs, nearly opposite, had the stem been free. Now
the whole rose from the upper side only. Long shoots, bearing cells with
hydrac, were at the same time vegetating from the lower extremity of
other two sections.

CAMPANULARIA. 223

Thus, hydrae are generated from descending as well as from ascend-
ing parts of the Sertularia dumosa. I know not whether this may be
found a feature more peculiar to zoophytes with a compound stem.

Plate XXVI. Fig. 22. Sertularia (Campanularia) dvmosa.

23. Portion shewing the form of the cells : hydrse in decay.
2-1. Portion with the hydra displayed. This is the extre-
mity of a branch. Vegetating shoots, a.
25. Portion of another specimen, with cells and hydrse.
All these figures, except 22, are enlarged.

§ 4. Sertularia (Campanularia) syringa — Creeping Bell Coralline.
— Plate XII. Figs. 9, 10. — I find some difficulty in identifying this pro-
duct with what learned authors distinguish by the same name. The ac-
companying figures may be a guide to the truth.

In certain respects the syrincja falls within the characters assigned to
the genus Campamdaria, but not in others.

It always occurs, in as far as I have seen, as a parasite, ascending
other zoophytes like a slender thread, bearing cells with hydrae.

To the naked eye, the cells are like so many spines of horn colour,
but seldom contain living animals, which perhaps indicates their delicacy.
They are of a long and somewhat campanulate shape, with an even lip,
rising on short pedicles, from the stem or thread, with about four whirls.
The pedicles originate at a considerable distance from each other. The
hydra protrudes a long, slender, transparent body, crowned by about
16 muricate tentacula. That number has been ascertained as the com-
plement of several. I have not observed any of the hydrse with only
eight tentacula, which is, in fact, a very rare characteristic of any of the
marine bydraoid zoophytes. I do not deny its existence, however. Such
a number of muricate tentacula may be rather incidental than general.

The whirls are occasionally very distinct ; but I have never been able
to ascertain that they are in a twisted form or arrangement.

As the bell or cell does not fall on losing the hydra, its relation to the
animal seems different from that of some species of the Campanularia.

224 ZOOPHYTES.

Plate XII. Fig. 9. Sertularia si/ringa investing both sides of a section of the
Sertularia dichofoma.
10. Hydra and empty cells of another specimen.
Both figures are enlarged.

§ 5. Sertularia arcta — The Crowded Sertularia. — Pl. XLII.
— Much hesitation may be entertained regarding the correct position
of this product, which is apparently allied to some inteimediate genus
approaching the investing Fhistrce. But the Ascidian hydra of the Flustra
itself, denies its reception there : neither, for the same reason, can it be
confounded with the AlcyonidicB, to which, in perfection, it bears some
analogy ; for here the zoophyte is hydraoidal. Leaving its precise place,
for the present, the product is now introduced merely for the convenience
of associating it with other hydraoids.

It is generally found as a small, irregular, flattened mass, seldom of
regular figure, seated as a parasite on the angles formed by uniting
branches of the Sertularia falcata. The dimensions and the shape are
alike various. Sometimes it is six lines by two, if of an oval figure. —
PI. XLII. fig. 1 ; but rarely appearing so symmetrical. — Fig. 2.

In as far as I have yet observed, this mass consists of a single stratum
of long, curving, tubular cells, crowded closely together. — Figs. 3, 4.
Where best exposed, as on the margin, the curvature is most conspicuous,
that of some, there exceeding a semicircle. — Fig. 4.

A hydra with eight muricate tentacula occupies each cell, stretching
much beyond its circular orifice, but offering nothing else remarkable.
The complement of tentacula may be rated at eight, though some indivi-
dual hydriTc have ten.

This product is not common ; it has never occurred to me otherwise
than as a parasite ; and it may be readily overlooked.

Propagation. — Here, as in many preceding species, the perpetuation
of the species is effected through the medium of a planula, such as is pecu-
liar^ under some modification, to that which is the origin of zoophytes,
whose hydrse are provided with muricate tentacula. This animal appears

CAMPANULARIA. 225

in October and November. It is very minute, not extending the third of
a line, of vivid green colour, and at first of the wonted habits, form, and
aspect.

But instead of being generated within a pod or vesicles as others
from the hydraoidal Sertularise, its matrix consists of a congeries of cavities
or compartments, as seen in the surface of the mass. — Fig. 5. An aperture
being discovered in the middle of each after the planula has been dis-
charged, we may presume that no more than one is contained in a com-
partment.— Fig. 6.

These animals are extremely numerous ; at least 150 quitted a speci-
men during the last days of October and the beginning of November, — all
concentrating soon in a watch-glass.

When fresh and vigorous they are not distinguished by any noted
peculiarities, nor until in early preparation for the usual metamorphosis. —
Fig. 7. But important changes ensue as this advances, and they are such
as I have not witnessed in any other of the tribe. When the planulse are
about to remain stationary, the body becomes round and deeply annulated,
exhibiting a number of prominent segments, like the whirling lately de-
scribed as indenting the stems and branches of zoophytes. Then they
have much the appearance of minute green leeches, excepting in the rings,
their vivid green colour being still preserved. — Fig. 8.

In a short time one end of the planula forms an enlargement, while
the other is elongating. — Figs. 9, 10. A bud swells above, fig. 11, which
rising as a long cell, shews an internal hydra under different aspects in
progressive evolution. — Figs. 12, 13, 14. At length the whole organic
structure being perfected — the animal is completely unfolded. — Fig. 15.

As the hydra advances, two rings enlarge the body near the root,
and the origin of the head, which afterwards disappear on the attainment
of greater maturity. The lower extremity of each subject seems affixed
below ; the higher rises in a clavate form.

The concentrated multitude, fig. 15, in as far as can be observed,
does not consist of so many hydrse incorporated together, or united to any
common substance, in such a manner as to be compared, for example, to
the Flustra, all seem to be only in approximation.

VOL. I. 2 F

226 ZOOPHYTES.

The planula becomes motionless in about eight or nine days after
quitting the matrix ; and other seventeen or eighteen elapse before evolu-
tion of the hydra. Therefore this Sertularia reaches perfection in about
twenty-six days after the planula escapes.

;■ ■ When the whole planulse of a specimen have forsaken their compart-
ments, the mass affording them, previously of a green colour, is now con-
verted to grey. After the concentrated nascent hydrse disappear from
their cells, those in their decay seem to leave the bulbs at the root, as
bearing considerable resemblance to the mass of compartments.

All the preceding details apply to objects which are very minute.

No corresponding mode of proiDagation among zoophytes has hitherto
occurred to me ; and although the subject of repeated observation, it is
sufficiently interesting to merit further inquiry.

Plate XLII. Fig. 1. Sertularia Arcta. — The Crowded Sertularia.
2. Another specimen.
8. Margin of the same.
4. Margin of Fig. 1 .
6. Surface of a mass of compartments.

6. Portion of the same, showing the orifices left by the escape

of the planulae.

7. Planulae.

8. Planulae metamorphosing.

9. Nascent Sertularise from the Planulae.

10. Nascent Serlularise advancing.

11. Nascent Sertularise in further progress.

12. Nascent Sertularise with the hydrse protruding from the cell.

13. Nascent Sertularise far advanced.

14. Nascent Sertularise.

15. Nascent Sertularise, originating from the planulae, now come

to maturity.
All the preceding figures, except 1, 2. are enlarged.

ZOOPHYTES. 227

ASCIDIAN ZOOPHYTES.

Our attention has been hitherto directed principally to those Zoo-
phytes whereof the living tenant, if not to be absolutely identified with
the structure and habits of the hydrse of the fresh-waters, or with that
above described of the sea, certainly offers many essential points of corre-
spondence.

There are some other products equally meriting commentary, whose
animals, more elevated in the zoological scale, exhibit an organic frame of
greater apparent importance and complication, as if to discharge certain

higher functions.

But it cannot be affirmed that superior benefit is derived from the
multiplication and arrangement of such organic structure, or that functions
of greater utility are performed, than what are effected amidst the simpli-
city of humbler beings. The vital principle is neither stronger, nor is it
of longer endurance ; it is not less the subject of casualties ; the perpetua-
tion of the race is not less dependent on the circumstances wherein they
are placed; while the portion occupied by the others of simplest form to
our apprehension, is uninterrupted in the distribution of the animated

universe.

Human comparisons of perfection, therefore, are rather relative than
positive. None but the Creatoe can judge justly of the degree of per-
fection allotted to his creatures.

Scientific observers having devoted themselves to investigation of a
rude and shapeless animal product, the Ascidia, generally more like a
lump of inanimate matter, than a being endowed with vitality, they there
found a most curious and interesting internal organization, veiled by the
coarsest exterior. Now was a structure revealed, elevating this rude mis-

228 ZOOPHYTES.

shapen mass far above many creatures whose symmetrical parts and orna-
mental aspect were calculated to invite admiration.

The general correspondence of some of the internal structure of the
Ascidia, with that of the animated tenants of an extensive tribe of zoophytes,
suggested a distinction, whereby the latter should be denominated ascidian,
while the former, whose properties we have discussed, should be charac-
terised as hydraoids.

Although, in the strictest definition, this denomination, ascidiati,
might be rejected for animals so different in various important features,
it proves a convenient distinction. Naturalists will find many facilities
in its adoption ; besides the meagreness of language itself compels us to
admit much, especially for avoiding circumlocution, which would be other-
wise rejected.

Farther, it is impossible to assume every trivial characteristic assign-
ed by each transient, or even each permanent observer, to the favoured
subject of his studies as a distinctive feature whereon some leading divi-
sion of the animal kingdom shall repose. Nor will such projects, now too
common, perhaps, prove lasting auxiliaries to science, until the learned
coincide completely on those to be held decisive.

Herein, I conceive, more intimate knowledge of individual species,
that which is only to be gathered from the preservation of individual
specimens, is requisite, than we have yet attained. Therefore we cannot
dispense with endeavouring to procure the multiplication and the corro-
boration of facts. No doubt this costs the sacrifice of time and trouble,
but the reward is durable.

In regard to the ascidian zoophytes, I shall abstain from attempting
to detail the anatomical structure of their minute inhabitants, which has
been done so well and so satisfactorily by others. It is always of difficult
detection and demonstration in the living specimen, nor to be otherwise
accomplished than by simple inspection, when transparency of the dwelling
and of the integuments of the creatures exposes the interior, — an oppor-
tunity very seldom offered. On considering such an obstacle, invincible in
many, I cannot but remark that a degree of precision sometimes appears
in the representation of internal organization, which seems to be deduced

ZOOPHYTES. 229

rather from presuming what the internal parts ought to be, at least in cer-
tain respects, than from truly discovering what they are. The resemblance
presented is only a modification, of which the skilfril microscopician may
convince himself ; yet we cannot deny that it may approach the fact.

For satisfactory elucidation of the structure and history of some
Ascidian zoophytes, let me refer the reader to the very copious memoir
of an intelligent author, Dr Farre, in the Philosophical Transactions for
1837, together with the useful abstract and illustrations by Dr Johnston,
in his general treatise on British Zoophytes. In the former, the anatomy
of several species is distinctly explained ; and a few notices relative to the
propagation of the respective genera, all accompanied by numerous figures.

Perhaps the subject of the ascidian zoophytes should be introduced
with some more special commentary on the form and the habits of the
Ascidia itself. But independently of their combination with a foreign
substance, which I have not seen in any of the Ascidia proper of Scot-
land, the tenants of that substance are, not real Ascidiae, being only parti-
cipants in certain analogies, nor these of a very intimate kind.

No greater apparent difference can separate two animals of opposite
genera than the external character of the Ascidia proper and the ascidian
zoophyte. The former resembles a mass of mere inanimate matter, com-
monly rooted to the same spot or substance, which it is incapable of quit-
ting. It scarcely betrays the rudest indication of any propensities or
instincts. All its changes, alterations, and actions are confined to an al-
most insensible enlargement of the body from the absorption of water,
slight dilatations of its orifices for the reception and discharge of muddy
matter. The rigidity of the body of the majority of the Ascidiae restrains
either its distention or contraction. Their whole sensations seem more ob-
tuse to external impressions than those of most living creatures. Hence are
their habits and configuration so little calculated to invite notice ; nor
until stripped of the coriaceous exterior covering, is the curious internal
structure laid open to the beholder. Hence also is almost all that has
been said of the ascidian tribe confined to anatomical formation.

As I shall probably resume a few general observations on the Ascidia
in a subsequent section, the reader may be here referred to the ample in-

230 ZOOPHYTES.

formation on both the simple and compound genera, contained in the works
of M. Savigny and M. Milne Edwards, together with the notices by Mr
Lister in the Philosophical Transactions for 1834.

Whoever views the Ascidian tenant of zoophytes, will be forcibly im-
pressed with the noted difference of its whole appearance, nature, and
habits, from those of the animal just referred to. It is full of life and viva-
ceous activity, readily quitting that retreat wherein its numerous tender
flexile organs are temporarily contracted, for security. The gentlest touch,
even modifications of the intensity of light, are sufficient for the display of
acute sensations. It can manifestly exhibit its apprehension of danger
and its conviction of safety. Its numerous parts are shewn in rapid mo-
tion, as if in quest of sustenance, and the exercise of some of the vital
functions may be occasionally discovered, while its most prominent orga-
nization is subject to continual and instant changes.

Thus the nature of the product is very different, it is almost directly
opposed to that of the Ascidia proper.

The inorganic portion, that is the polyparium, foundation or dwell-
ing of some Ascidian zoophytes, admits of narrow comparison with that of
the hydraoidal race. Possibly on a very comprehensive view, a parallel
might be found in the majority. But others, in this country at least,
])resent much variety both in form and substance ; and we seem as yet to
be in absolute ignorance of the real connection or relation of the different
])arts with each other.

The elements compounding that portion and the arrangement of
the parts, seem more numerous. These elements, to consider them gene-
rally, are membranaceous, gelatinous, or calcareous : they appear in flat-
tened surfaces, elevated in tubular cylinders, rising in lobate masses, or in
a foliaceous form, besides assuming fistulous shapes not remote from those
of the Sertularia;.

From this variety naturalists have endeavoured to frame a vocabulary
or a kind of descriptive nomenclature, significant of the form of the dwell-
inof, combined with the structure of the tenants. But the obstacles to
their design, so excellent and so laudable in itself, prove almost insur-
mountable. Until common consent shall determine what is to be held a

ZOOPHYTES. 231

sufficient distinction, one class of observers can be hardly expected to sacri-
fice the features assumed, as predominant to those which are favoured
by another. Hence the perpetual vacillation, which renders it preferable
to admit some conventional terra, even though less appropriate, for there
cannot be an equal desire for its alteration.

On this principle, I shall refer to the tenant of the ascidian zoophytes,
in much the same signification, as to the hydra of the preceding tribes,
and also by the name of hydra. I am not insensible that, by such a lati-
tude, I stipulate for a license beyond the strictness which definition would
^llow, but that will prove more than compensated by the advantage of
avoiding circumlocution ; nor does it involve the reader in the slightest
perplexity. Besides, it obviates that intertexture of words meant to ren-
der an intricate compound expressive, though, in truth, they tend to en-
feeble and confound each other. The simplicity of definitions from name
and character, preserved by such skilful authors as Linnaeus, accustomed
to contemplate the grand scale of the animal world ; and of Otho Frede-
ric Miiller, viewing it in ample detail, merits modern observance.

The tenant of the hydraoid zoophytes is comparatively a simple ani-
mal ; its internal organization, as that of the hydra, if consisting of various
parts, seems very little understood. The tenant of the ascidian zoophyte,
where the cellular partition and integuments admit, is seen to be of more
complex structure, and by the same means we discover much diversity in
their nature.

While the ascidian hydra is quiescent, the transparence of some zoo-
phytes shews it contracted in the cell, doubled on itself, the tentacula
compressed together, and the orifice of its habitation closed. As it rises
to display its parts, the orificial membrane above is carried upwards, along
with the body, and dilates as the body unfolds, like the inverted finger of
a glove, turning outwards. Now, it may be observed, that the body of the
tenant is attached below, by ligaments regulating its rise and descent ; that
the orificial substance of the cell is a continuation of its external intesru-
ment, and is carried up from its union with the animal, until the closed
pencil of tentacula can display themselves. As the hydra sinks below,
the same skin drawn downwards, closes as an operculum over it, when the

232 ZOOPHYTES.

summit of the cell becomes a conical or an ovoidal prominence. It is dif-
ficult to render this intelligible without inspection of living specimens.

Now, the hydra reposes in absolute quiescence. Next, when rising to
display itself, a percussive action is exhibited by the expanded tentacula,
as if they were inflicting blows on something in their vicinity. The neigh-
bouring visible particles are attracted apparently by a vortex, and tossed
about among them. Then, also, it is discovered by microscopic aid, that
the surface of each tentaculum, instead of presenting mere inequalities or
the rauricate character, distinguishing that of the hydraoid zoophytes, is
bordered on each side by numerous cilia, or short and stout hairs : that
the particles coming in contact with them are transmitted along the bor-
der, upwards or downwards, or from one to another : and that they are
finally absorbed in the central mouth of the animal.

But this ciliated structure is to be recognised, in general, only under
favourable conditions, and by optical instruments of superior power and
quality. The effect, indeed, may be often seen while the cause is un-
known, insomuch that reputable observers, either from their own defective
vision, or ignorant of the proper means of assistance, have denied the pre-
sence of the cilia ascribed to such hydrse by more successful naturalists.

Since Dr Fleming directed the notice of observers to the functions of
the Cilia of zoophytes, others have assigned an important office to those
occurring on many different animals. The reader will peruse with much
interest the article Cilia, by a learned anatomist, deeply versed in the
history of the lower tribes, Dr Sharpey, Professor of Anatomy and Physio-
lo<Ty in University College, London, composed for the Encyclopaedia of
Anatomy and Physiology.

Doubtless, that creative power devising the wondrous structure of
animals, assigned some definite use to all their organs; but I know not
that these are yet completely disclosed to naturalists.

In many such products, a distinct view of the hydra itself is obscured
by the intervention of neighbouring parts : and the minute inspection of
some is impracticable.

I shall now proceed to offer a few general remarks on several genera
and species of the ascidian zoophytes, in as far as they seem to me to merit

CELLULARIA. 233

observation. Sometimes they are separated by very slight distinctions ;
the names proposed for them are so various, that every one must waver
greatly in their adoption, nor can I pretend to determine which is pre-
ferable. Much remains to be done in this respect, both in gaining ad-
ditional knowledge of the genera, and in the significance of the forma-
tion and nature of the species, to sanction the appellative more peculiarly
applicable. If selecting one, it is by no means for the purpose of dero-
ffatina: from the correctness of another.

§ 1. Cellularia (notamia) loriculata — Coat of Mail Coralline. —
Plates XLIII., XLIV. — This product occurs in large, thick massy tufts,
several inches high, and several inches across, so dense and confused, that
its peculiar structure must be ascertained from smaller specimens. I re-
gret that my inability to procure those of considerable dimensions of
suitable form, though an abundance of others may be had, compels me
to leave the best illustrations for a supplementary Plate. A few other
subjects are under similar circumstances; some of the Sertularia; were
sought for above ten years before obtaining specimens for the most satis-
factory representation.

The Cellularia loriculata generally assumes somewhat of a conical
fio-ure, whence the longest parts diverge from the lower half of the stem ;
they shorten upwards, and terminate almost in a point or obtuse vertex.
This seems the natural configuration; and even when luxuriance and
bushiness restrain the regular shape, wherever the extremities are free,
they are so distinguished. — Plates XLIII., XLIV. figs. 1, 2.

I have not observed the root of the adults of circumscribed or definite
form, farther than as a scale of very small diameter. The stem for some
short distanee above it exhibits irregular articulations, which are not evi-
dent in every specimen. — Fig. 3. Alternate branches with their subor-
dinate parts, the whole tending to the same general formation, originate
from the stem, fig. 4. enlarged. The cells, very low, scarcely projecting
from the level where situated, have an elliptical orifice ; they are arranged
nearly in pairs, opposed back to back, from which peculiar feature, Dr
VOL. I. 2 G

234 ZOOPHYTES.

Fleming, a practical observer, proposes to institute a genus Notamia, ex-
pressive of it. — Plate XLIV. fig. 5.*

Some analogy may be found between the general arrangement and
form of the parts of zoophytes unconnected by genera. The cells of the
Loricularia, an ascidian zoophyte, for example, are in such a position that
their tenants protrude in opposite directions. Nearly the like is seen in
the Sertidaria pumila, an liydraoid zoophyte, where the orifice of the cell
is considerably elevated. — Plate XXVI. figs. 15, 16.

A large specimen of the Loricularia is composed of numerous prin-
cipal and subordinate tufts, each of which would occupy a cone of smaller
diameter in proportion below than fig. 1.

The hydra is minute, lively, and active, almost transparent, or dingy
white ; it seldom protrudes from its dwelling, Avhich has scarcely any per-
ceptible margin. When doing so, twelve is the usual number of tenta-
cula displayed. Some have fourteen. The hydras rarely occur alive ; and
observations can be made only on the merest fragments, from interven-
tion of the numerous parts. The tentacula have a percussive faculty, and
the hydrse vanish in a moment.

If these ereatures have any reciprocal connection, the means whereby
they are united is undiscovered. Probably the cells from which they pro-
trude in opposite directions, are separated by thin parietes peculiar to the
successive pairs disposed on the twig. But owing to the inconvenient inter-
ception of the observer's view, from the multitude of parts, he is exposed
to much embarrassment in obtaining such a position as to allow satisfac-
tory delineation of the living specimens.

Dark umber-brown distinguishes the lower parts of this zoophyte ; a
shade of which, together with dingy white, pervades the remainder. New
accessions towards the extremities are pure white. Some specimens
present a more luxuriant and richer aspect from speckling ; perhaps owing
to the numerous hydra that have perished in their cells.

The substance of the product partakes of a calcareous nature.

* It would be highly beneficial to science, were Dr Fleming to complete his useful work
on British Animals. His definitions are so clear, explicit, and applicable, as to stamp
authority on the volume already published, and to prove it the result of correct observation
and laborious research. No one could be better qualified for the task.

m

CELLULARIA. 235

Plate XLIII. Cellularia (notamia) loriculata — Coat of ISIail Coralline.
Plate XLIV. Fig. 1. Specimen growing from a portion of sponge.

2. Branch.

3. Stem.

4. Branch.

5. Twig with cells.

6. Twig with hydrse.

All the preceding figures, except 2, are enlarged.

f 2. Cellularia reptans — Creeping coralline. — Plate XLV. — This
is a product whose curious, determinate, and elegant formation, eluding the
unaided vision of mankind, can be discovered only by microscopic means.
What idea can we entertain of the Power that planned and executed such
a wonderful species of architecture — so many edifices — such an arrange-
ment— together with the inhabitants that occupy them ! Here is pre-
sented a vast colony of living beings — all dwelling in peace — no one inter-
fering with another's safety. In the marvellous field of the animated
universe, every step unfolds some novelty arousing our admiration of the
works of the creation.

This zoophyte is generally established on others, especially on the
Flmtra foliacea. It rises an inch in height, by a very short stem, and
diverges as much into subordinate parts, all tending to dichotomous for-
mation, or each cleaving in two. — PI. XLV. figs. 1, 2.

The stem and all the rest of the parts are clothed with a double row
of cells, in alternate arrangement. Their orifice, nearly level with the
surface, is elliptical, and their higher extremity guarded by two or three
short spines A lively ascidian hydra, with twelve tentacula, inhabits the
cells, but exposing so small a portion of the body that its nature and form
are to be rather presumed from analogies, than described and demon-
strated. The tentacula are slightly recurved : they are endowed with a
percussive faculty : particles are attracted, tossed about and repelled, by
the hydra, which retreats instantaneously within its dwelling. The whole
product is of a dark brownish-yellow : the portion of the animal exposed

236 ZOOPHYTES.

is very pale, almost colourless : but the opacity of the cells precludes a
satisfactory view of their conteuts.

Some specimens appear speckled red.

The vegetative faculty of specimens, though abortive of animals,
seems to be denoted by numerous slender prolongations, scarcely grosser

than hairs.

Many minute beings seek shelter among the multitude of cells, from
whence they either issue forth occasionally, or are dislodged by the im-
purity of the water.

Besides its foundation on the Flustra foliacea, this Cellularia estab-
lishes itself on the external surface of various shells, or it finds a safe and
convenient nidus within some, such as those of the mussel and oyster, when

empty.

The specimen represented, being perfect, was selected from among

many.

Plate XLV. Fig. 1. Cellularia reptans — Creeping Coralline.

2. The same, enlarged.

3. Aspect and arrangement of the cells, enlarged.

4. Portion of the hydra which is exposed, enlarged.

§ 3. Cellularia fastigiata (Sertulaeia fastigiata, Linnatis). —
Plate XLVI. — It is often very embarrassing to determine the identity of
species, or whether a certain subject before us may not be a mere variety.

Spite of all precautions, I feel very sensibly that I have been some-
times misled by appearances ; whence, if our arrangements shall be guided
by the structure of the inorganic parts, when life has fled, I believe that
they will afford greater facilities than the animated subject.

We can readily account for embarrassments resulting from the mi-
nuteness and frequent indistinctness of the organs of zoophytes : from the
alteration of their relative position by age and increment, that elusory
characters are necessarily assigned to many, from different observers hav-
ing assumed younger or older specimens ; the barren or prolific : that vari-
ous portions of the same specimen, where common features peculiar to

r..xi,v.

CELLULARIA. 237

each, have been taken : that absolute identity of features, in fact, does not
exist ; or remains to be unfolded. All this must conspire to embarrass one
observer, when in quest of what has been described by another, to say no-
thing of the difficulty of distinguishing accidental from natural vegeta-
tion, the influence of the seasons ; and especially as we have yet to learn
those periods of the year when, in preference to others, our enquiries
regarding particular points — such as the multiplication of individual species,
may be profitably directed.

Unless in instances comparatively few, I cannot but conclude that we
are still insufficiently acquainted with numerous important facts and dis-
tinctions, those to be the basis of undeviating authority. Thus, instead of
pronouncing the identity of species, which no doubt would simplify our
treatise, it is, meantime, better to keep them apart until obliterating equi-
vocal by positive characteristics. Should this be practicable, the present
zoophyte can be easily conjoined with the subject of the fifth paragraph,
as the fourth is purposely interposed.

This species has been denominated a Scrfiilaria, a Flustra, and a
Cclhdaria, by different authors. It rises two inches or more in height, by
a short stem, sustaining a bushy and somewhat globular head. Several
principal boughs subdivide into branches, which multiply in subordinate
parts. The older portion is of an umber colour, the extremities being
lighter, and, if new, they are white. A fine and entire specimen bears
much resemblance to an aged tree in miniature, whereof there is a slight
convergence above and an expansion from below. — PL XL VI. fig. 1.

The structure of this product, in detail, approaches the dichotomous
formation, or cleaving of the principal into two subordinate parts. But it
is somewhat irregular in respect to different portions, as will be seen from
fig. 2 to 7, inclusive.

Cells are ranged on one, and occasionally on both sides of the subor-
dinate parts ; but here also without uniformity. — Figs. 3, 4. A large
cylindrical or slightly tapering spinous process prolongs the exterior edge
of the cell, whose presence may denote perfection : thougli it is absent in
some specimens apparently entire.

The parts are irregularly articulated, but no precise relation is to be

238 ZOOPHYTES.

discovered between the articulations and the cells ; there is no definite cor-
respondence in number or extent.

A hydra, with a pencil of 16 or 18 tentacula, rises within, to display
them from the orifice of the cell, which is so transparent as to expose its
almost colourless, long, tapering body, afiixed by ligaments to a remote
point below, figs. 8, 9. One or two fine vermilion ovular substances are con-
tained in the body of many, rising and falling along with it. Their na-
ture has not been explained. — Fig. 4. Numbers are free of them. The
hydra is alike lively as others, clasping its tentacula together when dis-
played, exercising them in percussive action, with all the peculiarities dis-
tinguishing the vigorous tenants of ascidian zoophytes.

The stem should consist of aggregated tubuli, to judge by the shoots
sent forth of the extremity, when sundered. At least 15 filamentous pro-
longations issued downwards from a section, ultimately extending much
farther in proportion than represented in fig. 10, and adhering to the ves-
sel wherein deposited. Meantime the opposite extremity was vigorously
regenerating hydrse within, and the avicularium without the cells.

All the higher parts are regenerated, as may be seen from different
specimens, in various stages, where the colours are contrasted. The re-
generations are of the palest grey, almost or entirely white. — Figs. 5, 6, 7.
This product occurs at an early period as a single stalk, not a line in
height, with its hydra displayed. Another hydra is generated, in the next
place, on the same side, and then a third still higher. The final modifica-
tion and arrangement of the parts belong to a later era.

A white, opaque globule rested on the oi-ifice of several cells of a
specimen obtained in the beginning of INIarch, during survivance of living
hydrte on other parts. Active avicularia, of which more particularly here-
after, were also dispersed over it. — Fig. 11.

Specimens are frequently stained with red patches. If any be at
first pale, they become soon deep coloured : the hydrfe are found dead, and
the avicularia motionless. Those thus distinguished are very beautiful.

The parts intercept each other so much, and are so numerous, that the
smallest fi-agments only can be taken for microscopical observations.

This zoophyte is always rooted on solid substances. It is not common.

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CELLULARIA. 239

Plate XLVI. Fig. 1. Cellularia fastigiata.

2. Portion shewing the arrangement of the parts.

3. Portion with hydrse.

4. Portion with hydrse, shewing the formation of the cells :

also the distribution of the avicularium.

5. Higher portion regenerated.

6. Higher portion with regenerated hydrse and avicularium.

7. Higher portion regenerated with hydra.

8. Hydra.

9. Hydra.

10. Section generating descending shoots.

11. Section with hydrse, globular substance on the cells, and

avicularia.

12. Avicularium in repose.

13. Avicularium active.

All the figures except the first are enlarged.

§ 4. Cellularia ciliata — Ciliated Coralline. — Plate XL VII. —
None of the numerous tribe of Corallines can exceed the symmetry,
elegance, and beauty of this interesting product waving amidst the waters.
The singularity of its partg and proportions, seem to have originated with
the vigorous efforts of a sportive organic nature.

The general appearance of the Ciliated Coralline is a minute and
nearly circular fan, sustained by an undulatory stalk, with a slight recur-
vature from its weight and expansion. — PL XLVII. fig. 1. ; fig. 2. en-
larged.

It seldom surpasses nine lines in height, and is somewhat less in diver-
gence. At a considerable distance above the root the stem cleaves into
two boughs, each of these into two branches, and every branch into two
parts. Thence the arrangement is strictly dichotomous, or by successive
cleaving in two. — Figs. 3, 4. An harmonious and admirable symmetry re-
sults from this simplicity, and the subdivision advances still farther, though
the ultimate distribution of the minuter component parts becomes inde-
finite.

Each of all the multitude of parts is bordered by a double row of
cells in alternate arrangement. The orifice of the cell is elliptical, and

240 ZOOPHYTES.

guarded by five iiicurving spines of extraordinary length, originating from
its upper margin. — Figs. 4, 5. So great a profusion of long, slender,
delicate needles, combined with their peculiar form and position, impart
a soft and silky aspect to the whole product, which, to the eye, resembles
the minutest fern.

The length of the spines equals six, ten, or even twelve times the
diameter of the orifice of the cell. They are longest and more multiplied
towards the extremity of the branches, where their accumulation and
crossing intercepts a distinct view of the adjacent parts. Those below are
commonly impaired ; and the length and number of those above are fre-
quently irregular, either from natural or accidental causes. However, the
true complement of each cell may be rated at five.

An ascidian hydra of corresponding nature with the others described
in this chapter inhabits the cell. It is colourless, or of the faintest grey,
provided with from 12 to 14 rather flattened, slightly recurved, ciliated, and
percussive tentacula. But the animal is so vivacious and so restless, as to
render inspection by the microscope very inconvenient, and it altogether
disturbs that stillness which is essential for the study of the artist. There-
fore to obtain complete and perfect delineation of all the parts is imprac-
ticable ; interception, and motion combined with their multiplicity, are per-
petual obstacles. An opaque reddish or brown ovular substance appears
in the body, rising somewhat along with its ascent in the cell. Many
vacant cells also contain a dark globular substance at the bottom. Seve-
ral authors are disposed to conclude that what is thus seen as a residuum,
is the body of the hydra remaining permanently after death. But I have
not understood that in either case the nature of the substance is sufficiently
ascertained. Hydra;, no doubt, sometimes die in retreat, nevertheless
their soft and perishable organs, for the most part, waste away impercep-
tibly.

White corpuscula, very minute, and some of larger dimensions, have
been produced in vessels containing specimens of this zoophyte in August
and December. They swim actively, and in most respects resemble those
described in the next paragraph. One which admitted of closer inspec-
tion, proved opaque under the microscope, of soft a]>pearance and variable

CELLULARIA. 241

form. Some were like an obtuse-angled parallelepiped, apparently pro-
vided with a ciliated apparatus below, in front. It was difficult to attempt
following their history. Stationary globules have been likewise observed
among the parts of specimens, but numberless interceptions prevented a
distinct view of them. — Fig. 7.

In early stages the product exhibits a singular formation, as may be
seen in various nascent specimens, which originated on each side of the
stem of a different zoophyte. — Fig. 8. A second long cell seems belong-
ing to the first, both apparently guarded by a greater number of spines
than peculiar to maturity. — Figs. 9, 10.

The root is formed of forking radicles. — Fig. 11.

Many avicularia, which are extremely minute and transparent, border
the different parts of this Cellularia.

Plate XLVII. Fig. 1. Cellularia ciliaia — Ciliated Coralline.

2. The same enlarged.

3. Branch.

4. The same enlarged.

5. Branch of another specimen.

6. Portion showing the arrangement of the cells.

7. Corpusculum.

8. Nascent Cellularia in different stages.

9. Nascent Cellularia further advanced.

10. Nascent Cellularia still farther advanced.

11. Root.

All the figures of this Plate, except figs. 1 and 3, are en-
larged.

§ 5. Cellularia avicularis — Bird's-head Coralline — Plates XLVIII.
XLIX. — I refer to this subject with considerable hesitation. It has rather
appeared to me a different species from the Cellularia fastigiata, but the
point must remain open for discussion.

Ellis, in Plate xxxviii , wishes to identify the " Bird's-head Coralline,"
fig. 7, with a preceding species, represented by him Plate xx. fig a, A.
But the latter is either the fastigiata, or the subject of this paragraph ;
while the former, fig. 7, seems the Flustra Murrayana.

VOL. I. 2 H

242 ZOOPHYITES.

In those places to whicli I have had access, the product here named
Cellularia aviculari'^, has always grown as a parasite on the Flusira trun-
cata, a foliaceous zoophyte. I do not recollect observing it elsewhere, which
shews either that the same conditions are favourable to both, or favourable
to the particular kind of developement then attained by the avicularis.

In studying zoophytes, it is necessary to reflect, that developement
is much governed by situation, which has the greatest influence both on
dimensions and perfection.

On the leaf of the Flustra truucata, this product assumes somewhat
the form of a pine or larch, rising above an inch in height by a short stem,
around which the boughs are disposed, rather in a spiral arrangement.
The second originates a little above the first or lowest, a third still higher
than the second. All shorten in proportion as higher, with a slight incur-
vature of both the interior and exterior parts towards the stem, so that
the whole form of a perfect specimen is conical. — Plate XLVIII. fig. 1.
XLIX. enlarged. But this is not alike definite in smaller specimens.
All the subordiate parts terminate in a cell, whicli, in perfection, seems
to be guarded by three marginal spines. Some have two, many only one.
Possibly three form the complement. The root runs superficially over the
Flustra, secured by four radicles.

As in the Fastigiata, the dichotomous configuration and relative posi-
tion of the parts must be sought for more conspicuously by the aid of the
microscope. — Plate XLVIII. figs. 2, 3.

A lively ascidian hydra with 14, 15, and, I believe, sometimes 16 ten-
tacula, inhabits the cells. — Figs. 4, 5. Numerous brown ovoidal corpus-
cula remain in those which are vacant ; and a spherule rests on the ori-
fice of many, also vacant, where there is no room for more. This is brownish,
or paler and thinner as if empty.

A number of Avicularia bordered the branches of the specimen. —
Plate XLVIII. fig. 1, such as described in the following paragraph.
They appeared smaller than ordinary, and were at first motionless, though
displaying sufiicient activity two days after. — Fig. 6.

Dingy yellow, brown, red, and grey are agreeably contrasted in the
various parts of the product.

CELLULARIA. 243

Several minute, white, opaque corpuscula, probably gem mules, ap-
peared in different vessels receiving the specimen. They were solid and
consistent, obviously soft, as shewn by slight alterations of the shape.
Under magnifiers of considerable power, the body proved more cubical
and obtuse than spherical, begirt by numerous short cilia in rapid motion.
Two hairs or spinous processes, much longer than the cilia, apparently ori-
ginating below, came in view from certain positions of the animal. The
corpuscula move swiftly, shooting in a moment beyond the field of the
microscope.

Fine specimens of this zoophyte are rare.

Plate XLVIII. Fig. 1. Cellidaria avicularis.

2. Portion shewing the dichotomous formation.

3. The same enlarged.

4. Hydra, profile.

5. Hydra, front.

6. Avicularium.

7. Corpuscula or gemmules.

All these figures, except figs. 1, 2, are enlarged.

XLIX. Fig. 1. of Plate XLVIII. enlarged.

Perhaps the Flustra Murrayana, subsequently described, might be ap-
propriately introduced here, from some apparent kindred to the preceding
subject. But it is of more foliaceous texture ; and, as frequently said,
this treatise being only a collection of detached memoirs, not a system,
any particular zoophyte may receive its proper place when it becomes
sufficiently familiar to observers.

A very indefinite section seems to result from such a character as
CeUularia.

\ 6. Avicularium.— Plates XLVI. Figs. 12, 13 ; XLVIII. Fig. 6.
— ^The subject of the preceding paragraph has received its specific name
from the presence of a singular organic body, which cannot fail to at-
tract the notice of all observers. Its position and nature prove the source
of much embarrassment, together with the peculiar and unaccountable
motions which it exhibits.

244 ZOOPHYTES.

Perhaps the Avicularium may be ultimately found a generic charac-
ter. In as far as I know, it belongs chiefly, if not exclusively, to the genus
we have left, as instituted by later naturalists, the Cellularia, and hence
connected with the ascidian hydrse. We find it on the ciliata, the fast i-
giafa, avicidaris, just described, and the Flustra Murrayana. All with
cells guarded by spinous processes.

Much obscurity hangs over the true nature of the Avicularium. But it
is obviously of animal organization, and endowed with spontaneous motions.

From its external position and utter dissimilarity to the rest of the pro-
duct where affixed, we should at first sight deem it a parasite ; nor can we
discover any immediate connection between it and the living tenant of the
zoophyte.

The Avicularium is always seated on the outside and about the middle
of the cell. I have never seen it otherwise. Also, if the leaf of the
zoophyte be composed of a longitudinal series of parallel cells, it is borne
on each margin of the leaf, or on one margin only.

This organization, presents the strongest resemblance, in extreme
miniature, to a bird's head, as denoted by its name ; nor is the comparison
much impaired even by powerful magnifiers.

It then seems to consist of three distinct principal organs, first a
basis a, founded on, or incorporated with the cell ; next a head b, connect-
ed with the basis ; and, in the third place, a lower mandible c, demonstrat-
ing the most lively action. — Plate XLVI. figs. 12, 13, a, b, c.

In quiescence, the whole is like the head of a bird with the bill closed.
In activity, the lower mandible opening, folds back with a very wide gape.
Another joint apparently connects the head with the basis, wherein the
neck moves as in a socket. The bill opens and closes frequently ; the
spectator would say, for the purpose of absorbing some extraneous matter,
too minute or too refined for detection by human sense.

The motion is of two kinds, the whole avicidarium bending backwards
and forwards ; when the head sometimes reclines as far back in proportion
as seen of a bird reclining its head between its shoulders. The other motion
is merely the opening and closing of the lower mandible, widely gaping,
and continuing thus, but stationary, when the whole zoophyte has perished.

AVICULARIUM. 245

These movements are sometimes so lively, that notwithstanding the
excessive minuteness of the Avicularia, the agitation of several at once,
proves very inconvenient for microscopical observation. Though nume-
rous on a specimen, not above one individual has been seen on any single
cell. In itself it is semitransparent. Farther than already described, no
subordinate parts have been detected. Whether they exist, must be in-
ferred from future discovery of its real nature. Meantime, we must allow
that much embarrassment attends all attempts to account for the presence
of these objects. Are they parasites affixed immovably to a certain spot ?
Are they an integral part of the zoopliyte ? What relation do they bear
to the cell or to the hydra ? Such points are of no easy solution. For a
long time, I was induced to conclude the Avicularium a parasite — for
there are animals, like the lepas or barnacle, and some other cirrhipedes,
whose parts are incorporated with wood, rocks, or shells. I cannot believe
that it is connected with the hydra, from finding it seated and active on
the side of those cells wherein there are none. Nevertheless, it is an in-
tegral part of the zoophyte, in so far as being generated along with new
or reproducing portions. This, indeed, does not exclude the character of
a parasite ; for I have undei-stood that those infesting the larger animals,
sometimes occur in the foetus. — PI. XL VIII. fig. 6.

Without following the progress of the Avicularium, it could not be
recofnised from any resemblance between its earlier and later stages. At
first, it appears as a convex or hemispherical knob, crowning a cylinder.
While still farther advanced, it remains of imperfect form, triangular and
of light grey colour. Symmetry is afterwards attained.

Many were regenerated or reproduced on portions of the Cellularia
fastigiata.

A few remarks on a flexible organ sometimes issuing from the Ccllii-
Inria scruposa, are meantime reserved.

Plate XLVI. Fig. 10. Avicularium, quiescent.

1 1 . The same in activity ; basis, a ; head, b ; mandible open, c.
XLVIII. 6. Avicularium.

These figures are enlarged.

246 ZOOPHYTES.

Cluster or Social Ascidian Zoophytes. — Plates L.,LI., LIT. —
The definite figure, number, and arrangement of the parts, have enabled
naturalists to detach a few zoophytes from the general enumeration, ai^d
to unite them in lesser sections.

One of these has been constituted by Dr Fleming, under the name
I 'rilheria, which other authors incline to preserve, as sufficiently expressive.

This, in a more extensive sense, comprehends those zoophytes with
cells approximated in groups or clusters, inhabited by an ascidian hydra
with eight tentacula : to which may be conjoined some with similar tenants,
but numerously arranged in rows on the different inorganic parts.

By a remarkable disposition of Nature, masses or clusters of animals
belonging to the same product are generated at considerable intervals,
without any intermediate channel obviously connecting them.

But the more distant cluster, being of later evolution, and the cells
nearest to the preceding being the larger and more mature, affords some
presumption of the vital principle of the one being derived from the other
developed before it, and conveyed by a secret communication.

Here the skeleton seems to participate more of the substance of that
of the Tubularia and of the Pedicellaria than of the skeleton of the Cel-
lularian race.

As one leading feature of this section is the number of tentacula be-
longing to the hydra being definitely eight, the Imbricata, Cuscuta, and
Leitdicjeva, fall properly within it : and the same characteristic distinguish-
ing the Spinosa, will sanction its annexation. My observations on a few
of these, also with eight tentacula, are not sufficiently mature for a sepa-
rate paragraph.

\ 1. Valkeria imbricata. — Plate L. — The naturalist in commemo-
ration of whose name this genus is instituted, was a clergyman of the
Church of Scotland, established at Moffat, a village in the county of Dum-
fries, celebrated for the medicinal wells in its vicinity. These have been
very long in great repute for alleviating various distempers, and are now
much resorted to, especially in the summer season. Having been sent

ZOOPHYTES. 247

thither for a serious infirmity, in early youth, I recollect the natural
productions likely to stimulate my juvenile curiosity, which were dis-
played in the threshold of Dr Walker's dwelling. The Chair of Natural
History, which is among the later academical institutions in the Univer-
sity of Edinburgh, becoming vacant, Dr Walker was appointed to fill it.
On his demise, the present worthy and learned Professor Jameson, whose
useful labours have contributed so effectually towards the advancement
of science in Scotland, was chosen to succeed him.

The Valkeria imbricata rises erect, about two inches in height, by a
short stem, and then subdivides into slender boughs, waving slightly, with
branches in alternate arrangement on their opposite sides, originating
from the convexities. — PL L. fig. 1.

Masses or clusters, composed of a double row of cells, wind spirally
up the surface of the skeleton, at irregular intervals. This peculiar order
is distinct in their earlier stages, but with the increment and accumulation
of cells, the spiral progress, and the disposal of the cells in pairs, become
less evident ; it is gradually obscured, and finally lost. — Fig. 2.

The cell, of ovate form, is occupied by an ascidian hydra, with eight
ciliatsd tentacula. The cilia are stout, and very conspicuous, as their
successive action is exhibited, fig. 3.

As the cell is connected with the body of the ascidian hydra, whether
by ligaments below, or by the union of the margin above, it undergoes a
great modification with the position of its tenant. When the latter is
displayed, the cell is extended : when in retreat doubled on itself, the cell
becomes ovate.

The stem seems tubular. Its extremities are obtuse. But neither
the surface of the stem nor that of the cell is smooth.

Finer specimens exhibit numerous subordinate parts, of which the
most remarkable are the clusters of cells. One an inch higli, bore be-
tween 60 and 70 such clusters, with their hydra;. Another, an inch and
three quarters high, had 19 clusters on a single branch. The former spe-
cimen spread about an inch. But, in studying the subject in detail, it is
better to select more meagre specimens, where the multiplicity of parts
does not intercept the view.

248 ZOOPHYTES.

The clusters are generated and formed after a singular manner. One
may consist of sixteen or twenty cells, winding in pairs up a branch in a
slight spiral direction. As the vegetation of the obtuse extremity of the
branch advances, the clusters originate on it in prominences still lower and
nearer the root. The first or lowest pair of cells is the largest ; the other
pairs, in winding up the stem, diminish gradually to extreme minuteness.
Thus did one series exhibit 8 pair or 16 originating cells : another 3 pair
only, being probably in an earlier stage. As they advance, they become
greenish or yellowish to the eye, and on approaching maturity, the in-
cluded embryo becomes perceptible.

The subsistence and maturity of a lower cluster seems to be essen-
tial for the propagation and evolution of a higher cluster. This may af-
ford room for speculation, whether the vital principle is not awakened in
the germ of the hydra, or whether some depositation of elements, to be
thus brought to maturity, be not effected by the vigour of the parts, as the
vegetative power advances the stem whereon the new series shall originate.

Besides the groups dispersed on this product, in various numbers,
sometimes a straggling single cell may be seen.

A yellowish or greenish colour pervades the whole zoophyte. The
clusters are yellow : the cell transparent, its tenant faint yellow, as is evi-
dent while contracted within.

The product appears as a parasite, or rooted independently on solid
substances.

I am informed that it is abundant in some of the Scotish Seas. But
I have never found it so. On the contrary, it has been rare.

Plate L. Fig. 1. Valeria imbricata.

2. The same, enlarged.

3. Hydra, enlarged,

^ 2. Valkeria cuscuta. — Dodder Coralline. — Plate LI. Figs. 1, 2.
— Another cluster-zoophyte, much more common than the preceding, ap-
pears as a very minute pendulous chain, of a greyish colour to the naked
eye. I have never seen it erect, its slenderness and flexibility, indeed, being

:i|

4'

ZOOPHYTES. 249

such that it cannot sustain itself unsupported ; whence, it either hangs as
a parasite from other marine substances, or stretches along the surface of
shells.

The stem, no thicker than a human hair, extends sometimes an inch
and a half in length. It is smooth and tubular, seldom with any branches ;
though specimens do occur with several, and then they diverge to right
and left.

Numerous clusters of from six to eight or ten ovate cells are im-
planted on the stem and branches, at intervals, and occasionally with con-
siderable regularity. The cells may be also seen in pairs, when one cell is
on each side of the stem. Here the clusters are more numerous, and in
nearer approximation to each other, than in the species above described.

An ascidian hydra, with eight cUiated tentacula, occupies the cell,
which, like the other, is prolonged on its protrusion.

This zoophyte is commonly of dingy white or greyish colour.

The specimen represented did not exceed half an inch in length.

Plate LI. Fig. 1. Valkeria cmcuta, magnified.
2. Hydra magnified.

The reader will find some interesting remarks by Dr Fleming, in the
Memoirs of the Wernerian Society, vol. iv. p. 485, PI. xv.

J 3. Valkeeia lendigera — Nit Coralline. — Plate LII. — The name
Syrinoc or Paris Pipe, would have been more characteristic than any
hitherto given to this zoophyte, from the intimate resemblance of some of
its parts to that instrument, — presuming the species now described to be
identified with that of preceding naturalists.

I am aware that it is proposed to institute a new genus Serialaria,
which shall include the species before us. But as this seems to have been
done in ignorance of the nature of the hydra belonging to it, and the ge-
neral features being common to what the Valkeria may comprehend, per-
haps its true place is very near to this section, and may be included here.

VOL. I. 2 I

250 ZOOPHYTES.

The Syrijiiv, Pan's Pipe, or Lendicjera, consists of a very slender stalk,
from which a meagre distribution of boughs and branches originates irregu-
larly. At certain intervals, also, irregular enlargements are seen on the
various subordinate parts, but so minute, that their general form is scarcely
to be recognized as definite by the eye. The whole product is about two
inches high, expands as much, and is of faint dingy yellow. — PI. LII. fig. 1 ;
fig. 2, enlarged.

Under the microscope, the indefinite enlargements on the subordinate
parts, are found to consist of a double row of cylindrical cells, with an ob-
tuse summit. Though generally described as in a double row, their real
arrangement is in partial alternation, the convex side of one being applied to
the opposite recess formed by the union of two, somewhat like the position
of two rows of cells in a honeycomb. Few having attended to this, most
probably has given rise to the proposed genus Scrialaria.

Fourteen or fewer cells, compose a group or alternate double series.
The number in the group diminishes towards the extremities of the parts.
But the greatest number is not limited to fourteen : some groups contain-
ing more. The cells of the series shorten as they ascend, because the
lower cells come first to maturity. The disparity, however, is less evident
among the older of the series, though very conspicuous among the younger
or higher. Their origin and increment corresponds with what is seen in
the cells of the hnbrlcata. Larger specimens of the zoophyte bear 50 or
60 groups. The sustaining stalk extends beyond the farthest group by
prolongation, preparatory for new accessions. From vigorous vegetation
the obtuse extremities sometimes adhere to whatever they reach.

The intervals between the groups are bare and transparent. But the
surface of both the stalk and the cells is speckled.

An ascidian hydra, with eight tentacula, inhabits the cell, which rises
in active evolution, like the others, carrying up the convex summit of the
cell along with it. The orifice of the cell is connected with the margin of
the body, so that, in the rise and fall, they are in continual depen-
dence. A row of specks seems to traverse the middle of the tentacula.
Buoyant particles are tossed about among the hydrse, and when received
by the mouth in the centre, their deglutition becomes sensible, from trans-

ZOOPHYTES. 251

parence of the body, which is scarcely darker than the surrounding
element.

This product is founded either independently on shells, or it grows as
a parasite on other zoophytes. It is frequently so closely interwoven with
a variety of matter, as to render the extrication of specimens entire a very
difficult task.

I have never seen the cells of any specimen ranged in a straight line
as a single series, nor otherwise than alternately.

Plate LII. Fig. 1. Valkeria Undigera,

2. The same enlarged.

3. Another specimen.

4. Arrangement of the cells, enlarged.

5. Hydra enlarged.

§ 4. Valkeria spinosa. — Silk Coralline. — Plate LI. Figs. 3, 3. — This
is a fine and elegant product, of the most delicate texture. It rises seve-
ral inches in height, bounded for the most part by what might be the form
of a narrow cylindrical vessel, containing a living specimen. But the parts
are so numerous, so minute, and intercept the view of each other to that
degree, that only a very small section can convey their figure and arrange-
ment under the microscope.

All have a slight incurvature towards the slender stem : their extre-
mities terminate in prolongations like thorns.

This is not a cluster or social zoophyte, however : for numerous single,
long, ovate, transparent cells, stand in a row on one side of the subordi-
nate parts. As the higher are of smaller size than the rest, probably they
come to maturity successively, like some of the preceding. Sometimes
there are eight or ten in a row.

The cell is occupied by an ascidian hydra, with eight long transpa-
rent, ciliated tentacula, alike quick and lively in its motion with others of
its race. But it is extremely timid and reluctant to shew itself The
shape of the cell alters much by its retreat, becoming somewhat irregular,
and smaller towards the orifice. It is rarely to be obtained alive. Per-

252 - ZOOPHYTES.

haps the same may be said of all the more minute hydrse, for they must
be very readily affected by transitions of site, or the alteration of tempe-
rature. When withdrawn from the water, the largest specimen merely
resembles a quantity of wet moss.

The natural colour is grey, with the faintest tinge of pink.

It occurs in great profusion, and sometimes many of the hydrae are
alive and vigorous.

Specimens were kept from the end of September until the beginning
of January, when the vessel, a tall narrow jar, being emptied of its con-
tents, at least 50 minute specks were seen adhering to the sides on re-
plenishment. They tended to an elliptical form, and several exhibited
small white projections. A very minute hydra, with eight tentacula, after-
wards sprung from one of them.

Plate LI. Figs. 3, 3. Valkeria spinosa. Extremity of a branch, enlarged.

This is a single extremity, cleft down the middle, to obtain
room for it on the Plate.

NOTE.

There is commonly much irregularity in the position of single cells,
of pairs of cells, or of masses and clusters of them, even in all subjects.
Certainly this denotes a great inequality of the vital forces. It might be
ex])ected that in genera and in species uniformity should prevail, whereas
only analogies are presented, and, for the most part, those but of a remote
or general character.

The jireceding genus, Valkeria, embraces ascidian hydra? with eight
ciliated tentacula. Another genus of ascidian hydrse, but with ten ciliated
tentacula, is proposed under the name of Bowerhankia or Laqemlla.

Considerable general resemblance appears between the hydrte and
cells of these two. But more minute and accurate examination may prove
their difference in other points, though the number of tentacula coincides.

Two species, if I be not mistaken, both with ten tentacula, inhabit

ZOOPHYTES. 253

the Scotish seas, but, from having had very few, I can say little regarding
either.

Dr Farre proposes here to constitute a genus Bowerbankia, including
two species, the repens and the densa. But in Dr Johnston's opinion, the
characters specified are scarcely sufficiently definite to justify the distinc-
tion between them. However it seems well founded.

1. Bowerbankia repens. — Plate LIII. Figs. 1, 2, 3. — The general
character of this product, in as far as I have seen it, participates somewhat
of the nature of the Valkeria cuscuta, in the appearance of the stem and
distribution of the cells.

A slender stalk rises slightly above the surface of old shells, or runs
irregularly over it. — Plate LIII. figs. 1, 2. From this there originate single
cells, and cells in pairs or in clusters, the whole irregular in position and
number. — Fig. 3. The cell is occupied by an ascidian hydra with ten ten-
tacula. Being apparently identified with the hydra of the following species,
farther commentary on it is unnecessary.

This zoophyte is dingy white.

2. Bowerbankia densa. — Plate LIII. Figs. 4-12. — The general aspect
of this species is somewhat diversified. It invests other marine substances
as a parasite, sometimes totally overspreading them, with rather a mossy
appearance. But I have not observed its form confined by any such de-
finite outline as will admit its reference to familiar objects, which may
be seen from two specimens represented of their natural dimensions. —
Plate LIII. figs. 4, 5. Accumulated hydras cover the surface invested.

A magnified view of the upper portion of fig. 4, is given fig. 6 ; and
a transverse section of fig. 5, also magnified, in fig. 7. The whole seems
an accumulation of single cells.

The body of the hydra protrudes very far. The cell is much altered ;
while the animal is in retreat, it is long, with an ovoidal summit, which
stretches upwards as the hydra rises to display ten active ciliated tenta-
cula.

From the great protrusion of the body, and the transparence of the

254 ZOOPHYTES.

integuments, modern naturalists have followed Dr Farre in assuming this
creature as a type for illustrating the structure of ascidian hydrse.

The specimen fig. 5, exceeded 18 lines in length, and 2 in diameter,
while the animals were quiescent. Owing to their extraordinary multi-
tude, no part whatever of the substance invested was visible among them.
It was studded by the interspersion of numerous yellow corpuscula. But
I could discover none in the body of those hydras manifesting vigorous
animation, though one was contained in each cell of many where the
tenant had decayed.

Here it may be remarked, that when certain ascidian hydrte lose
their vigour, the organic portion wastes away, leaving behind it a long ob-
tuse hollow cone, containing fertile ova. It is in a similar cone of the
preceding species, fig. 3, that an ovum appears. In the present species
the precise position was obscured. But in the other, there is a remarkable
correspondence with the nature of the Alcyonella stagnorum. When cor-
puscula or gemmules were discharged from the zoophyte under discussion,
I failed in observing how they escaped. But a most accomplished practi-
cal naturalist, M. Van Beneden of Louvain, while giving the anatomy of
the hydra at large, in his Recherches sur les Bryzoaires, shews the termi-
nation of the oviduct under the root of the tentacula. I deeply regret
that my very recent acquaintance with only some of this learned Profes-
sor's valuable and interesting works, has prevented me from availing my-
self suitably of many useful observations, which I can no otherwise repair
than by earnestly recommending their perusal to those desirous of real in-
formation.

Though I did not observe how the ovum was discharged, nor whether
as such, or as an active corpuscular gemmule, for this might have pre-
ceded my inspection, I found it of ovoidal form, truncate behind, and be-
girt by cilia. It was also apparently heavy, solid, and consistent. Several
escaped during the course of observation from the specimen figs. 4-6, on
July 14, the day after it was obtained, fig. 10. Among these one, fig. 9, was
much occupied about a slender hair in the watch-glass containing it ; some-
times adhering, sometimes searching around, and evidently betraying what
any indifferent spectator would have pronounced its animal nature. Num-

ZOOPHYTES. 255

bers of such corpuscula continued to be discharged for above a week. Two
of these escaping previous to July 17, were then adhering to the watch-
glass, and in an early stage of metamorphosis, fig. 11.

As the metamorphosis and supervening increment are perfected and
advancing respectively, the form of the nascent hydra is clearly exposed
through the transparent integument. The body is then seen to be attached
by a number of ligaments to the bottom of the cell, and the pencil of the
tentacula approaching the summit, where the parts shall relax to allow dis-
play of the whole by protrusion on maturity. Descent of the intestinal canal
from the stomach, and its return upwards in conformity with ascidian or-
ganization, are very distinct, fig. 12. Here is a yellow substance resem-
bling an ovum at the bottom.

All the cells of this zoophyte are originally separate as those of the
Sertularia arcta.

When the corpuscular gemmules come to afiix themselves to some
slender substance, and there undergo their metamorphosis, the bases of
the generating cells are opposed to each other.

Neither of these two species has been of frequent occurrence in Scot-
land, but skilful naturalists seem to have found abundance elsewhere.

Plate LIII. Fig. 1. BowerhanJcia repens

2. The same enlarged.

3. Portion magnified.

4. BowerhanJcia densa.

5. Another specimen.

6. Upper portion of fig. 4 enlarged.

7. Section of fig. 5.

8. Hydra.

9. Corpusculum or gemmule.

10. Group of corpuscula.

11. Corpuscula metamorphosing.

12. Nascent hydra from a corpusculum.

All the figures of this plate, except figs. 1, 4, .5, are enhirged.

Whatever new names, whether original, modified, or altered, are found
in this volume, they must be regarded as mere temporary and provisional
substitutes, liable to such correction as expedient.

ANALYTICAL INDEX.

CHAPTER I.— HYDRAOID ZOOPHYTES, . . . page 1

§ 1. TCBDLARIA InDIVISA, ..... 2

Its head a hydra or polypus, with a double row of tentacula, 3

Head regenerated, ...... 4

Five heads regenerated successively, ... 6

Growth of the stem results from the hydra, . . . ib.

Regeneration originates low in the stem, ... 7

Propagation, ....... ib.

Ovarium situated on the head, .... ib.

Matrix, a cluster of cysts, . . . . . ib.

Embryo, or young discharged from the cyst, . . 8

Endowed with locomotion, . . . . . ib.

Animals originate from a vascular speck, ... 9

Institution of life, . . . . . .10

Animals originally transparent, .... ib.

Ovular form transient, . . . . . ib.

Zoophytes are of animal nature exclusively, . . 11

Nascent moving tubularia becomes rooted, . . . ib.

Head of Tubularia is deciduous, .... ib.

Prognostics of its fall, . . . . .13

The parent less protected than the progeny, ... ib.

Embryo or young expelled before the head falls, . . ib.

No second progeny generated in the cyst, . . . ib.

Season of propagation, . . . . .14

Fine ovarium in 1826, ..... ib.

Egg a wonderful device of nature, . . . . ib.

Creation of animated beings, . . . . 15

Regeneration from below, . . . . . ib.

The stem vegetates downwards at first, ... ib.

Elements of organization in the head, . . . . ib.

Six heads regenerated in six months, ... 17

VOL. 1.

2 K

258

ANALYTICAL INDEX.

CHAPTER I.— continued.

No vegetable flourishes and fructifies as ofteu,

No animal of similar regenerative fertility,

Second ovarium rare,

Pith, ....

Site of the germ ? . . .

Rudiments of the animal reposited below,

Several regenerations in simultaneous progress.

Root of the Tubularia,

It does not diffuse as in the Sertularia,

Diminished light impedes observation.

Effect of wounds and lacerations,

Monstrosities,

Regenerations multiplied by artificial sections,

Prolific elements found lower and lower in the stem.

Excisions pernicious, ....

Monstrosities, ....

Symmetry is restored, ....

J. D. Dana a modern learned author.

His observations on the form of bodies.

Monstrosities, . • • •

Tendency to symmetry.

No two bodies alike.

Elements of the hydra remotely situated,

Evolution and maturity depend on the pith.

Seven perfect hydras, one abortive, produced in 395 days.

Two generated in opposite directions.

Conclusions, ....

Reflections, . . . •

Plates I., II., III., IV., explained.

§ 2. TCB€LARIA LAKYNX,

Large bodies more easily examined than small,

Group like a tuft of flowers.

Hydra with a double row of tentacula,

Nascent Tubnlariae from ovarian cysts,

Hydra deciduous, ....

Seven heads regenerated in 66 days.

Degeneration concomitant on reproduction,

Theory of germs from vascular structure.

Defective uniformity,

Doris feeds ou the Tubularia larynx,

Mode of dislodging it, . . •

Plate V. explained,

PAGE 17

ib.
18
ib.
19
ib.
20
21
ib.
22
23
ib.
24
26
27
ib.
ib.
ib.
ib.
28
29
31
33
ib.
ib.
35
ib.
36
38

42
ib.
ib.
43
44
ib.
45
47
ib.
ib.
48
ib.
49

ANALYTICAL INDEX,

259

CHAPTER II. — TuBULARiA ramea,

It is rather a Sertularia,

Eudendrium a less appropriate name,

Specimen resembling an aged tree,

Hydra with a single row of 24 tentacula,

What are flexible zoophytes,

Vorticellse,

Inflexible compound stem,

Hydrse of Tubularia ramea regenerated,

Intervals of regeneration,

Minute objects difficult to be followed

Propagation,

Vesicles,

Single planula from a vesicle,

Larva a less appropriate name,

The planula is animated,

Planula metamorphosing.

Specimen bred from a planula,

The same animal difierently represented,

Competent artists rare,

Representations often more definite than the truth,

Tubularia ramea a beautiful object,

Its prolific nature, ....

Plates VI., VII., VIII., IX., X., explained, .

§ 2. Tubularia (Sertularia) ramosa,
Hydra with from 6 to 14 tentacula.
Circulation of a fluid visible,
Currents irregular,
■ Ascidia, .....

Medusa ocilia (8 tentacula).
Appearance and disappearance of Medusae,
Suspending objects in water convenient,
Nascent Medusa or pyrulum.
Evolution, ....

Circulation between the pyrulum and hydra.
Irregular circulation in the lower animals.
Provisions of nature,
Grandeur of the universe,
All may be derived from simple elements,
Medusa Sexdecilia (16 tentacula),
Hydrse generate Medusae,
Plate XI. described,

PAGE 50

ib.
ib.

51

53

ib.

54

ib.

55

56

ib.

57

ib.

58

ib.

59

60

ib.

ib.

ib.

61

62

ib.

ib.

64

ib.

65

66

ib.

ib.

ib.

ib.

67

ib.

68

69

ib.

ib.

ib.

70"

71

ib.

260

ANALYTICAL INDEX.

CHAPTER III.— The Hydra, ok Polypus, .... page 73

Hydra a conventional name, . . . . . ib.

This work is a collection of memoirs, ... ib.

Dr Johnston's partition of Zoophytes, . . . . ib.

Two species of fresh-water hydrge in Scotland, one in the sea, 74

Nature of all three corresponds, . . . . ib.

Hydra gelatinosa, tuba, and strobila, are the same animal, . 76

§ 1 . Hydra tuba, the Trumpet Polypus,
Miiller, Sars, Lesson,
British Association at Edinburgh, 1834,
Hydra, analogies of, with the Actinia,
Food, .....
Senses obtuse,

Propagation, ....
Generates in its own likeness.
Reproduction in the vicinity of the stomach.
Embryo buds from the parent,
Sertularia encreases like the hydra.
Colony of 83 Hydrffi from one parent,
Eight the original complement of tentacula,
"Works of Nature resolve into simplicity.
Lost parts regenerated.
Each of two halves becomes perfect.
Symmetry always restored.
Conclusions from experiment.
Propagation depends on sustenance.
Imperfect animals do not propagate.
Colonies observed during years.
Plates XIII., XIV. explained,

76
ib.
ib.
77
ib.
78
82
ib.
ib.
ib.
86
87
88
89
90
91
ib.
93
95
ib.
96
97

§ 2. Origin op the Hydra tuba.

Type of the multiplication of zoophytes,
Vorticella, Plates XII., XXII.,
Hydra tuba larger than other hydrse,
The parent survives posterity.
Medusa or Sea-blubber,
Certain species noxious, Plate XV.,
Its progeny resembles the planula,
Progeny metamorphoses to the Hydra tuba,
JIultitude of planulae in ovarian sacs.
Young hydra has eight arms or tentacula,
Eleven prolific Medusae, Plate XVII.,

99

ib.
100

ib.

ib.
101
102
103
105

ib.

ib.
106

ANALYTICAL INDEX.

261

CHAPTER in.— continued.

Multitude of planulfe from tliein, . . . pagf, 106

Scum on the surface of the water secreted from the planulse, 107

Natural position of the hydra, . . . . ib.

Twelve tentacula acquired in 40 days, . . .109

None of 2000 hydrae acquired more, ... ib.

Suitable treatment of living subjects, . . . . ib.

Medusa is the parent of the Hydra tuba or Strobila, . 110

§ 3. Medusa bifida, — origin, . . . . . ib.

Period of its appearance, . . . . . Ill

Variety of Medusae, . . . . . .112

Baster observed Medusa bifida in 1761, . . . ib.

Black specks rather glandular than ocular ? . . .113

Medusae bifidse are transient, .... ib.

Survives 55 or 60 days, . . . . . ib.

Medusa bifida originates from the Hydra tuba, . . 114

Pendulous roll of Medusa3 forming there is gradually dissolved, . 116

Basis remaining permanent becomes a hydra, . . 117

Period occupied in dissolution, .... ib.

Old tentacula obliterated, others evolved, . . . 120

Production of pendulous roll, . . . .122

How and where is it generated ? . . . . 123

Obstacles to prosecuting the history of the Medusa, . . 1 24

Number in the roll, . . . . . 125

Roll dissolved, basis perfected, . . . .126

Bulb or basis become a hydra surviving above a year, . 127
Monstrosities of the Medusa?, .... 128

Medusa and hydra of different nature, ... ib.

Conclusions, . . . . . . .129

Plates XVIII., XIX., XX., XXI., explained, . 130

CHAPTER IV.— The Sertclaria, ....

Zoophyte of comprehensive signification.

Numerous inorganic combinations with the same animal,

Nomenclature changed, ....

Addition of species preferable to midtiplied genera.

Precipitate nomenclature.

Animated portion of zoophytes overlooked,

Dr Johnston corrects this error.

Analogies of Tubularia and Sertularia,

134

ib.
135

ib.

ib.
136
137

ib.
13S

262

ANALYTICAL INDEX.

CHAPTER IV. — continued.

Instincts and habits of the hydra,
Luxuriant Sertularia interesting,
Pith obscures the skeleton,
Ascidian, asteroid, hellanthoid hydra.
Life of Sertularia dependent on the pith.
Entire specimens rare,
All originate from a single hydra,
Differences, anomalies of young and adults,

§ 1. Sertularia Polyzonias,
Hydra with 24-26 tentacula,
Attempts to feed it, .

Alledged food of zoophytes,
Vesicles with 24 spherules,
Hydrae from their planulae,
Hydrse regenerated,
Plate XXII. explained,

I'AliE 139

ib.

ib.
140

ib.
141

ib.
142

143
144

ib.
145
146

ib.
148
149

§ 2. Sertularia Abietina,

Every animal product is peculiar.

Genus — variety.

Hydra with 24 tentacula,

Syme's P., Nomenclature of Colours,

Compound and simple vesicle.

Shallow vessels for microscopic objects.

Root of the Sertularia,

Hydra developes from the pith.

Lowest flourishes first,

Hydra survives a month,

Compound ampullate vesicles,

Planulse of variable shape.

Evolution within vesicles in situ is rare,

Ellis' figures explained.

Are prolific vesicles permanent ?

Young hydra; surviving a month,

Plates XXIII., XXIV., XXV., explained,

150

ib.

ib.
151

ib.

ib.
152
158
154

ib.

ib.
155

ib.
156

ib.

ib.

ib.
157

3. Sertularia abietinula.

Narrow distinction of zoophytes,
Hydra with 18 tentacula,
Irregular articulations.
Vesicles of various shape,

157

158
ib.
ib.
159

ANALYTICAL INDEX.

263

CHAPTER lV.—co)itinued.

§ 4. SeETDLABIA rosacea, ..... PAGE l.Dtl

Hydra with 22 tentacula, . . . . • 160

Vesicles large and peculiar, . . . • . ib.

Metamorphosis of the planula from them, ... ib.

•Plate XXVI., figs. 1-13, ib.

§ 5. Sertularia pumila, . . . • • .161

Articulation is a pair of cells, .... ib.

Hydra with 19 or more tentacula, . . . .162

Globular and ovoidal vesicles, .... ib.

Plate XXVI., figs. 14-21, ib.

§ 6. Sertularia ualecina and Cognates, . . . 162

1. This species is indistinctly characterized, . . .163

Plate XXVII., il'-

Hydra with 18-22 tentacula, . . . • . ib.

Regenerating hydras develope from the summit of the pith, . 165
Number regenerating from a twig, .... ib.

Propagation, . . . • • ■ 166

Vesicles, green and yellow, of various configuration, . . ib.

Green and white planulaj from the same specimen, . . ib.

Metamorphosis of the planula, . . . . .167

Spine from the smaller extremity, .... ib.

Anomalies — peculiarities, . . . . . ib.

DiflTerent vesicles on the same specimen, . . . 168

Three hundred nascent Sertularia) in February, . . .169

Hydra; issuing through vesicles, .... ib.

2. Sertularia (T/ioaJ Beanii, . . . ■ . ib.
Hydra with 20-24 tentacula, . . . ' . ib.
Vesicle peculiar, . . . • . .170
Planula metamorphosis to Sertularia in si.x days, . . ib.

3. Cognvitea ol Sertularia halecbin, . . . .171

Stem consisting of tubuli, . . ... . ib.

Vigorous regenerations, . . . . . ib.

Specimen with 400 yellow vesicles, .... ib.

Colour of the vesicle from its contents, . . . .172

Planuloe discharged during weeks, .... ib.

Origin of vesicles obscure, . . . . .173

External impressions on hydraj, .... ib.

Sertularia halecina favourable for observation, . . . ib.
Plates XXVII., XXVIII., XXIX., XXX., XXXI., explained, 174

§ 7. Sertul-^ria muricata, . . . . .175

Hydrai with 22-24 tentacula, .... ib.

2(34

ANALYTICAL INDEX.

CHAPTER lY .—continued.

Peculiar vesicles, . . . . . imge 175

Minute solen always present, . . . . 176

Plate XXXIl. explained, . . . . . ib.

§ 8. Sertdlaria (Plcmularia) falcata, ... ib.

Species recently constituted genera, . . . . ib.

Distinctions to be founded on important features, . . 177

Trivial differences of no avail, . . . . . ib.

Falcata stem, length compared with its diameter, . . ib.

Regenerations white, . . . . . . ib.

Hydra with 15 or 16 tentacula, . . . . 178

Vesicles with white and yellow contents, . . . ib.

Contain 1-7 planulae, ..... ib.

Planulse are living animals, ..... 17.9

Cilia inconspicuous from insufficient niaguifiers, . . ib.

Five cells from metamorphosed planula, . . .180

Planuke surviving 27 or 28 days, . . . . 181

Analogies in generation of Sortularia) and Medusas, . . 182

Tendency of planuloe to ascend, . . . • 183

Disparities of young and adult Sertularia, . . . ib.

Plates XXXIII., XXXIV., explained, . . 184

§ y. Sertularia (Plumularia) pinnata, . . . . 185

Hydra with 20 tentacula, ..... ib.

Irregular shaped vesicles with a yellow corpuscuhim, . . ib.

Plate XXXV. explained, . . . ■ ■ 18G

§ 10. Sertdlaria (Plumdlaria) fascis, . . . . ib.

Stem of aggregated tubuli, . . . • • 1^7

Hydra with 25-27 tentacula, . . . . . ib.

Generation by ascent and descent, .... ib.

Tendency to vegetable growth, . . . • .189

Vesicles, ....... ib.

Plate XXXVI. explained, . . • • . ib.

§ 11. Sertularia argentea, . . . . • ib-

Knowledge of zoophytes slowly acquired, . . .190

The tallest of Scotish zoophytes, .... ib.

Specimen 27 inches high, . . . • .191

Hydra with 20-22 tentacula, .... ib.

Propagation, . . . . • • .192

Compound vesicle, ...... ib.

Multitude of planulge, ...••• 193

ANALYTICAL INDEX. 265

CHAPTER IV. — continued.

Metamorphosis, ..... page 193

Adults and young different in form, . . . . ib.

Vegetation, . . . . . . . 194

Germinating principle a year dormant, . . . .196

Animal and vegetable analogies, .... ib.

Conclusions, . . . . . . .197

Plates XXXVII., XXXVIII., explained, . . . ib

§ 12. Serttjlaria.antennina, ..... 198

Planulae the origin of zoophytes with muricate tentacula, ib.

No anticipation of ultimate dimensions, . . . 199

Multiplication follows animation, . . . . ib.

1. Antennina, Jjohster'ahoTii, .... ib.
Hydra with 14 tentacula, ..... 200
Cell nearest the stem first prolific, .... 201
Embryo most distant least mature, . . . . ib.
Ovate vesicle — single planula, .... ib.

2. Sertularia ( Ncmcrtesia ) ramosa, .... 202
Stem composed of tubuli, . . . . . 203
Vigorous reproductions, . . . . . ib.
Analogy of zoophytes to vegetables, .... ib.
Decay commences with extremities, . . . . ib.
Mode of propagation guides to character, . . . 204
Vesicles of S. antennina and ramosa contrasted, . . 205
Vesicles contain 24 or 30 planulae, . . . . 206
PlanulsB resemble planarioe, . . . . . ib.
Three different vesicles on S. ramosa, . . . 208
Lamouroux's specimens dried fragments, . . . ib.
Plates XXXIX., XL., explained, .... 209

CHAPTER V. — Campanclaria, . . . .211

Indelible characters should distinguish genera, . . ib.

Genera precipitately instituted, . . . . ib.

§1. Sertulakia (Campandlaria) dichotoma, . . 2)2

Its luxuriance, . . . . . ib.

Its parts originally white, . . . . . 213

Bell falls with decay of the hydra, . . . . ib.

Hydrae and bells regenerated, . . . . 214

Propagation, . . . . ■ • .215

Tintinnabulum (Medusa J generated in the vesicle, . ib.

Progress of its evolution, . . . . .216

VOL I.

2l

266

ANALYTICAL INDEX.

CHAPTER V continued.

Its life transient, . . . . .

Figures by Ellis and Mr Lister, .
Are S. dichotoma, Geniculata, Gelatinosa, different ?
Plate XLI. described, ....

§ 2. Sertularia (Campanularia) verticillata,
Bell decays along with the hydra,
Hydra regenerated, . . . . ,

Vesicles, .....

Planulte, .....
Young specimens are finest,
Campanularia is a character too indefinite,
Plate XII. figs. 1-8 explained,

§ y. Sertdlaria (Campanularia) dumosa.
Hydra with from 8 to 14 tentacula,
HydrsB develope from vigorous pith,
Hydros generated by ascent and descent.
Plates XXVI. figs. 23-25 explained,

§ 4. Sertularia (Campanularia) syringa,
Bell or cell permanent after losing the hydra,
Plate XII. figs. 9-10, ....

§ 5. Sertularia arcta.

Its position doubtful, ....

Hydra with 8 tentacula,

Green planulse produced from it, . .

Matrix of the planulte.

Metamorphosis of the planulae in 26 days,

Plate XLII. explained.

PAGE 217
ib.
ib.
ib.

218
219
220

ib.

ib.

ib.
221

ib.

ib.

222
ib.

223
ib.

ib.

ib.
224

224

ib.

ib.
225

ib.
226

ib.

ASCIDIAN ZOOPHYTES,

Simple and complex organization.

The Creator alone can judge of perfection,

Ascidia resembles an inanimate mass.

Internal organs,

Ascidian zoophyte a convenient distinction.

Internal structure rather presumed than provfcl.

Dr Farre, .....

Dr Johnston, ....

Ascidian zoophytes and Ascidia not identical.

M. Savigny, M. Milne Edwards,

ib.
ib.
ib.
ib.
228
229
ib.
ib.
230
ib.

ANALYTICAL INDKX.

-207

232

ASCIDIAN ZOOrilYTES— <;ow«iMM«(^.

Polyparium of Ascidian Zoophytes, . • i'ace 230

Nomenclature vacillating, . . • ■ • -31

Linna3HS, Otlio Frederick Miiller, . . - ■ id
Cilia, ...•■■•
Dr Sbarpey, . . • - •

Creative power determined the use of organs, . • . ib.

Farther investigation essential, . ■ • • 233

§ 1. Cellulabia (Notamia) loriculata, .... ill-

Dr Fleming a correct original observer, . • • 234

Hydra with 12 or 14 tentacula, . • • • . ib.

Plates XLIII. XLIV. explained, .... 235

§ 2. Cellularia reptans, ... . . lb.

Wonderful formation of dwellings for animals, . - 'b.

Works of the Creation admirable, . • • . ib.

Hydra with 12 tentacula, . • • • • '°-

Vegetations abortive, ..•••• -•"'''

Plate XLV. explained. . . • • • ^^'•

236
ib.

§ 3. Cellttlaria fastigiata, ....

Delusive appearances, . . . • •

Inorganic parts may guide to system, .... ib.

Embarrassments, ...••• '"•

Multiplication of species inexi)edient, . ■ • .23/

Hydra with 16 or 18 tentacula, .... 238

Plate XLVI. explained, . • • • .239

§ 4. Cellularia ciliata, . . . ■ • 239

Five orificial spines ou the cell, . . • • • 240

Hydra with 12 or 14 tentacula, . . • • il*-

Delineation difficult, . ■ • • • . ib.

Plate XL VII. explained, ..... 241

§ 5. Cellularia aviculabis, . • • • . ib.

Is it different from Ce^^M^aria/as^iairt ? . - • • 'h.

Three spines on the cell, ..•••• 242

Hydra with 14-16 tentacula, . ■ ■ • '^■
Avicularium, ..••••■'"•

Flustra Murrayana, ..•••• 243
Plates XLVIII., XLIX. explained, . • •

ib.

ib.

§ 6. Avicularium, ..•■•••

May prove a generic character, . • ■ • .244

Kesemblance to a bird's head, . . . . ib.

268

AN/VLYTICAL INDKX.

ASCIDIAN ZOOPHYTES— continued.

Produced along with generated parts, . . . page 244

Object on Cellularia scruposa, .... 24.5

Plates XLVL, XLYIII., ib.

CLUSTEK OR SOCIAL ASCIDIAN ZOOPHYTES, ... 246

Masses of cells at intervals, . . . . . ib.

Hydra with 8 tentacula, ..... ib.

§ 1. Valkeria imbricata, . . . . . . 247

Dr Walker, ....... ib.

Professor Jameson, . . . . . . ib.

Numerous clusters on V. imbricata, .... 248

Lowest cells and hydrae first mature, . . - . . ib.

Plate L. explained, ...... ib.

§ 2. Valkeria cuscuta, ...... 248

Stem slender as a hair, ..... 249

Hydra, ........ ib.

Plate LI., ....... ib.

§ -3. Valkeria lendigera, . . . . . . ib.

Bears 50 or 60 groups of cells, .... 2.50

Mode of increment, . . . * . . . ib.

Plate LII., . . . . . . . 251

§ 4. Valkeria spinosa; . . . . . . ib.

Specimen resembles wet moss, .... 252

Young produced in January, . . . . . ib.

Bowerhankia or Lagenella, . . . . . ib.

1. Bowerhankia repens, ...... 253

Hydra with ten tentacula, ..... ib.

2. Boicerhankia densa, . . . . . . ib.

Hydra assumed as the type of ascidian form, . . . 254

Hydra with ten tentacula, . . . . . ib.

Ovum of B. repens, ...... ib.

Professor Van Beneden's works of high quality, . . . ib.

Ova B. densa, ...... ib.

Gemmules or corpuscula, . . . . . ib.

Metamorphosis, . . . . . . 255

Connecting ligaments of hydra and cell, . . . . ib.

Plate LIII. explained, ..... ib.

END OF VOLUME I.

TO THE BINDER.

The Binder will place the Plates thus :—

Plate I. Tubularia Indivisa, to front

II. Tubularia Indivisa, .

III. Tubularia Indivisa,

IV. Tubularia Indivisa, .
V. Tubularia Larynx,

VI. Tubularia Ramea,

VII. Tubularia Ramea,

VIII. Tubularia Ramea,

IX. Tubularia Ramea,

X. Tubularia Ramea, .

XI. Tubularia Ramea ; Medusa Ocilia,

XII. Miscellaneous Zoophytes,

XIII. Hydra Tuba,

XIV. Hydra Tuba,
XV. Medusa,

XVI. Proge/iy of Medusa,

XVII. Medusa .

XVIII. Medusa bifida,

XIX. Hydra Tuba, Medusa bifida,

XX. Hydra Tuba, Medusa bifida,

XXI. Vorticella,

XXII. Sertularia Polyzonias,

XXIII. Sertularia Abietina,

XXIV. Sertularia Abietina,
XXV. Sertularia Abietinula, .

XXVI. Miscellaneous Zoophytes,

XXVII. Sertularia Halecina,

XXVIII. Sertularia Halecina,

XXIX. Sertularia Halecina,

XXX. Sertularia Halecina,

XXXI. Sertularia (Thoa) Beanii,

XXXII. Sertularia Muricata,

XXXIII. Sertularia (Plumularia) Falcata,

XXXIV. Sertularia (P.) Falcata,
XXXV. Sertularia (P.) Pinnata,

XXXVI. Sertularia (Plumularia) Fascis,

XXXVII. Sertularia Argentea,

XXXVIII. Sertularia Argentea,

XXXIX. Sertularia (Nemertesia) Antennina,— Ramosa

Page 2
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270

Plate XL. Sertularia (N.) Ramosa,

XLI. Sertularia (Campanularia) Dicliotoraa,

XLII. Sertularia Arcta, ....

XLIII. Cellularia Loriculata, ....

XLIV. Cellularia Loriculata,

XLIV. A. Cellularia Loriculata (Supplemental, referred to p.

XLV. Cellularia Reptans,

XLVI. Cellularia Fastigiata,

XLVII. Cellularia Ciliata,

XLVIIL Cellularia Avicularis,

XLIX. Cellularia Avicularis, .

L. Valkeria Imbricata,

LI. Valkeria Cuscuta,

LII. Valkeria Lendigera,

LIII. Bowerbankia, ....

2.33)

PAGE 210

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236
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