'i

Library
of the

University of Toronto

.

A

Digitized by the Internet Archive
in 2017 with funding from
University of Toronto

https://archive.org/details/dropsofwaterthei00catl_0

TE>

:v.

1. rioecularia ornata.

6 . Tolyarthra trigla .

11 Rotifer vulgaris .

2. Limiuas eeratopAylli-

7 . RattuAus- luuaris .

■ 12. Actmurus- Neptuuv

3. Micro eoloit ela,vus .

8. Lepalella ovalis .

13. Noteus cjuadricorius

4. Notommata lougiseta .

9. Mastigocerca cariuata .

15. Aiurrffia souaimjla.

5. SyncLseta -jectiuata .

10. Salpina mucrouata .

16. PterocLma -patina.

2Ue*t

(C ,7,1c.

Achilla oLtl it Zith.

DROPS OF WATER;

THEIR

MARVELLOUS AND BEAUTIFUL INHABITANTS

DISPLAYED BY THE MICROSCOPE.

BY

AGNES CATLOW,

AUTHOR OF f POPULAR CONCHOLOGY,’ c POPULAR FIELD BOTANY,’ &C.

“For Nature here

Wanton’d as in her prime, and played at will
Her virgin fancies.” — Milton.

LONDON :

REEYE AND BENHAM,
HENRIETTA STREET, COYENT GARDEN.

1851.

PRINTED BY REEYE AND NICHOLS,
HEATHCOCK COURT, STRAND.

DEDICATION.

This slight introduction to one of Nature’s inexhaustible
sources of wonder and delight, I inscribe to three Sisters,
my affectionate friends ; who, by their cultivated minds and
kind sympathy, have so greatly enhanced my pleasure in
the pursuit.

Beaconsfield, March 1851.

Earth hath its Mountains, lifting high
Their viewless summits to the sky ;

Its Plains, that in their boundless maze,

Baffle the eye’s far-searching gaze ;

And Seas, immeasurably deep,

Which, in their secret holds, do keep
Treasures unknown to human thought, —
Treasures by human hands unsought.

Yet hath nor mountain, plain, nor sea,

In all their vast immensity,

More power to speak, through wondering sense,
Of the great God’s omnipotence,

Than one small drop of water ! — Yes,

Behold its living world ! (no less)

Of creatures beautiful and bright,

Disporting ’midst its liquid light.

Some, like to rare and clustering gems ;

Like lilies some, with silver stems,

Waving in graceful motion, slow,

(Like measured cadence) to and fro ;

Others like fairy bells appear,

Ringing their chimes in fancy’s ear ; —

And there are serpent-forms, that glide
’Midst tiny banks of moss, or hide
Their glittering coats beneath the leaves
Of mimic boughs, — which Nature weaves

By the same hand of power, that made
Tor man the mighty forest glade !

But vainly words essay to tell
What things of wondrous beauty dwell
Within these liquid worlds concealed.

Till by some magic spell revealed.

Come, watch the myriads as they pass
In bright review before the glass
Of wizard Science ! — then declare
If aught on earth, in sea, or air,

Can with these Water Drops compare. — C. P.

PREFACE.

Haying for several years derived great and in-
creasing pleasure from the use of a good micro-
scope, particularly in the investigation of the
minute creatures contained in water, and wishing
to extend this pleasure to others, I venture to
make public the following pages ; for though
there are several learned works already on the
subject, my experience and observations may be

PREFACE.

X

more genial to the beginner, than the scientific
treatises of more able authors. I shall be satisfied
if this little work is soon laid aside for those of
higher pretension and greater merit ; and I refer
the advanced student to the volumes by Ehren-
berg, Pritchard, and Mantell.

To give an idea of the wonders to be found
in this new world, to which I wish to lead
the reader, I shall describe one scene amongst
the many to be witnessed. My readers must
fancy themselves spirits, capable of living in a
medium different from our atmosphere, and
so pass with me through a wonderful brazen
tunnel, with crystal doors at the entrance.

PREFACE. xi

These doors are bright, circular, and thick, of
very peculiar construction, having taken much
time and labour to bring to perfection. A spirit
named Science opens them to all who seek her,
and feel induced to enter her domains. At the
end of the tunnel we find other portals, much
smaller, and more carefully constructed, and two
or three in number ; when these are opened, we
are in the new world spoken of. And now I
see your astonishment : your minds are bewil-
dered with the variety of new beings and forms
you behold, all gliding and moving about without
noise and at perfect ease.

Now let me direct your attention, first, to the

xii PREFACE.

vegetation you see around you ; and remark how
different it is from our own. Here is a plain
covered with a plant which resembles number-
less yards of green figured ribbon, in a state of
entanglement. If you examine the substance,
you find it composed of cells linked together
in myriads, each cell containing granules which
form the seed ; these cells in time break up,
the imprisoned grains come forth, and from them
arise new plants in countless numbers. Here is
another, much thicker, and of a different pattern.
Now we come to one, which, instead of being
round, like the others, is three-sided. Then look
on this — have we anything to compare to it? You

PREFACE. xiii

observe it is formed of two half-circular green
masses, joined together on the straight side by
a narrow band-like tube : you see it has neither
root, branch, nor leaf, and yet it is a vegetable.

Now we will turn from the inanimate, to ani-
mated beings. That wonderful living creature
you see approaching, is worthy of special exami-
nation. You exclaim, “ This is not a living
creature, but a miniature globe, rolling in this
new world into which you have introduced us.”
It has this appearance, certainly ; but that it has
sense, motion, and will, I think I can convince
you, and moreover that it is not one being alone,
but is formed of hundreds of minute beings, all

xiv PREFACE.

enjoying life, and grouped together in this
curious manner for mutual support. Let us ex-
amine it, and you will then be able to believe the
evidence of your own senses. You see before
you a hollow globe, formed of a material suffi-
ciently transparent for you to see within it.
Now look at the green dots with which it is
spotted thickly, but evenly, all over ; they are
living beings, attached to the inner side of the
globe, each having an eye and a double proboscis,
which it protrudes from an opening in the trans-
parent case, and by which it has communication
with the exterior, and obtains its food. See how
actively each moves this instrument, and what

PREFACE. XV

enjoyment they all seem to have ; their united
efforts also, continuously exerted, turn the globe
round, and thus the whole progresses rapidly.
Look within the globe, and you cannot fail to
observe, towards the centre, other smaller globes,
formed exactly like the larger one, being already
full of little individuals ready to enter on active
life. — Now you perceive the transparent case is
ruptured in one spot, and you fear the globe has
met with an accident, and will perish. On the
contrary, it is the prelude to new life. The
orifice becomes larger; the minute globes con-
tained within are making towards the opening :
now one has escaped, and now another; those

b

Xvi PREFACE.

have entered on an independent existence, and
are followed by the rest. But watch the little
individuals in the case ; you see they are also,
many of them, ready to assert their independence,
and are leaving their habitation. At last you
see the case lies shrivelled, useless ; — but I desist;
I see you are lost in admiration at only qne of
the creatures of this unknown world to which we
have paid a transient visit ; we will, therefore,
again beg Science to admit us through her brazen
tube, and open the crystal portals, that we may
pass into our own world; where, though we
meet with no creatures of a compound form, no
living globes, we find beings like ourselves, who

PREFACE. Xvii

will, when Nature is more closely and affection-
ately studied, be lost, like us, in wonder, love,
and praise.

Microscopists usually speak of the power of
their glasses in diameters, or what is termed,
also, linear dimensions; that is, the simple
measure across, instead of the compound or
superficial measurement: a power of 250 dia-
meters (quite sufficient for all ordinary purposes)
has a superficial measurement of 62,500. The
size of objects is calculated by parts of an inch ;
an animalcule may, therefore, be to, tto, or
even tsoqs of an inch in size : — this may be
ascertained by knowing the diameter of the

Xviii PREFACE.

field of view in tlie glass used. Further par-
ticulars may be acquired on this subject by
referring to works on the microscope.

1. Desmidium Swartzii. 7. Staurastrum cuspi datum

2. Micrasterias cLenticulata . 8. Closterium a ceTO sum .

3. Buastrurn. cfblongum . 9. Closterrom. Diam.Ee .

4. C o smaTium. m.argaritifer\vm.,10. Closterium. setaceum. .

5. SGantTuirum armatum . 11. Pediastrum pertusum .

G. Arthro lesmus convergens . 12. Pe dia. strum. Hapoleonis .

lS.'ETagilaria rlaalo 3,0 s oma .

13. -Scene desmus quadric an. data .

14. Navicula viridis .

15. Navicula ampkis’basTi.a .

1G. Navicula acns .

17. Bacillaria vulgaris .

18. Bacillaria cuneata .

AchilUs <Ztl clicks.

Jice.vc JYvcJio/s imp.

1)H(0)P 1 o

1. Desmidium Swartzii.

2. Micrasterias deuticulata .

3. Euastrum oplonguin. .

4. C o smariuni. maTgaritafeiu

5. 36aathi4mirL armatum.

6. Axtliro cLe sirius converg^nis

7 . _ Staur as trurn. Ausji datum.

8. Closteriuni aceTpsuiti
■9. Clo s'teriuTr. Lia.naj

.10. ClosteriuTn. setaceum

11. Pediastrum pertusunx

12. Pediastrum. PTapoleoms .
3 . PTagilaxla PhaPlosOma .

13. Scene&esTmis cjuadTicaixdaAa ,

14. Xs.vicala. viridis .

15. NavicuPu amjahisl) aena .

1G. Havicula acus .

17. Bacillaria vulgaris .

18. 13 acillarra cun. eat a .

AchilUs clel cc licks.

DROPS OF WATER.

l ~

No pursuit in the whole range of learning is more
congenial to the human mind than the study of
Nature. No one can gaze upon the beauty and
complexity of her forms without wishing to dive
more deeply into her hidden recesses, and, by in-
vestigation, to find out the cause of many won-
derful effects constantly brought before the eye.
Astronomy may raise our thoughts to the Creator
in wonder and astonishment by the magnitude of
the stars, and the marvellous wisdom by which
they are kept in their course ; but “ there are
miracles of minuteness as well as of magnitude,"

B

2 DEOPS OP WATEE.

and, as an old writer expresses himself, “ the ma-
jesty of God appears no less in small things than
in great ; and as it exceedeth human sense in the
immense greatness of the universe, so also doth
it in the smallness of the parts thereof/’

The wonderful power of the Creator is as
clearly manifested in the formation of the smallest
animalcule, as in that of the largest living being ;
and perhaps the former even excites our admira-
tion in a greater degree, for when we examine, by
the aid of “ that mighty talisman of wisdom ” a
microscope, an object which is so small that’ the
unassisted eye cannot discern it, or which the
point of the finest needle would destroy in an
instant, and find it perfectly beautiful in all its
parts, our wonder is the more increased, and the

THE MICROSCOPE. 3

mind is lost in astonishment at that power which
has brought such things to pass. The reflective
mind experiences great delight in the investiga-
tion of those minute objects, which to the unas-
sisted eye are invisible, but which, by the aid of a
good microscope, may be studied at ease ; our
curiosity, however, is never satisfied, for, though
by magnifying an object we find wonders re-
vealed which before were hidden, we know that
if our glasses were of a still higher power, we
should discover more of the mechanism, and find
out the use of many parts, that without this in-
creased aid would remain in uncertainty. As
our microscopes will probably never be made
sufficiently powerful to show clearly all the
minute creatures contained in water, we shall

4 DROPS OP WATER.

still remain ignorant of some of them. And this
fact forms a parallel case to that relating to the
stars ; for astronomers have informed us, that, by
the increased power of their telescopes, myriads
of stars have been discovered, beyond those seen
without this powerful aid, and that every year,
as the glasses are improved, more and more stars
appear : we may, therefore, in viewing the series
the other way, imagine with some degree of pro-
bability, that water may still teem with life even
beyond the reach of the highest powers of our
glasses, and we may never be able to say with
perfect truth of any drop of water, that it is
free from animal or vegetable life. The thought
is as overpowering in the one case as in the other,
and we should be thankful that, by the aid of

POWER OE THE MICROSCOPE. 5

science, such systems are laid open for our inves-
gation and study. Dr. Chalmers, in speaking of
these two wonderful instruments, says very im-
pressively— “ While the telescope enables us to
see a system in every star, the microscope unfolds
to us a world in every atom. The one instructs
us that this mighty globe, with the whole burthen
of its people and its countries, is but a grain of
sand in the vast field of immensity * the other,
that every atom may harbour the tribes and
families of a busy population/7

I cannot better commence this slight sketch
of some of the minute objects contained in
water, than in the words of Professor Jones. —

“ Take any drop of water from the stagnant
pools around us, from our rivers, from our lakes,

6 DROPS OF WATER.

or from the vast ocean itself, and place it under
your microscope : you will find therein countless
living beings, moving in all directions with con-
siderable swiftness, apparently gifted with saga-
city, for they readily elude each other in the
active dance they keep up, and, since they never
come into rude contact, obviously exercise volition
and sensation in guiding their movements. In-
crease the power of your glasses, and you will
soon perceive, inhabiting the same drop, other
animals, compared to which, the former were
elephantine in their dimensions, equally vivacious
and equally gifted. Exhaust the art of the
optician, strain your eye to the utmost, until the
aching sense refuses to perceive the little qui-
vering movement that indicates the presence of

ANIMALCULES. 7

life, and you will find that you have not exhaust-
ed nature in the descending scale. Perfect as
our optical instruments now are, we need not
be long in convincing ourselves that there are
animals around us, so small, that in all probabi-
lity, perseverance will fail in enabling us accu-
rately to detect their forms, much less fully to
understand their organization/7

These few pages are almost entirely confined
to the description of animalcules* found in water :
and as all, or very nearly all, are invisible to the
naked eye, no subject can be more interesting
than that of these wonderful atoms, which, we

* The word animalcule signifies little animal : Infusoria is a term
more generally used to designate these little creatures, as they abound in
all infusions of animal and vegetable matter.

8 DROPS OF WATER.

have every reason to suppose, are by far the
most numerous of those beings possessing life.
The variety of form, the extraordinary construc-
tion, the rapid movement of some, the stationary
life of others, and many other peculiarities, will
prove subjects of interest and delight to the
thinking mind. The one idea that a single drop
of water may afford amusement, and excite asto-
nishment for hours, to the investigator, is suffi-
cient proof of the wonderful powers of the Creator
in this minute portion of his works. These little
creatures prove quite fascinating ; and hour after
hour will be spent in watching their habits and
movements, till the powers of the student are ex-
hausted. A good microscope, in fact, opens a new
world to the possessor, a world of beings totally

A NEW WORLD. 9

different from anything we have been accustomed
to see ; and the substance of which they are
composed is in general so transparent, that the
internal structure is visible to the eye, — even the
act of digestion can be perceived, and the food
traced from its entrance at the mouth, to its
passage into the internal cavities ; the eggs, also,
can be seen within the body. These and many
other peculiarities have been discovered only
by very patient investigation* and several natu-
ralists, both English and foreign, have almost
devoted their lives to the study : and let no one
say it is a useless one, for whatever can help to
prove the power and wisdom with which this
world was created, cannot be time thrown away.
To those who only use the microscope as an

10 DROPS OP WATER.

amusement (and it is a never-ending one) a
short time occasionally is well bestowed on one
of the most beautiful parts of the creation.

There are upwards of seven hundred species
of Infusoria known and described. These are of
all shapes and forms, some even assuming a va-
riety in themselves ; many possess eyes, others have
none ; some move so rapidly that the eye cannot
follow them, and others are attached to various
substances ; some have very many stomachs, or
internal sacs, and others have only one ; others,
again, form a compound mass, that is, many in-
dividuals live in the same transparent case, and
some are so minute that by the aid of the best mi-
croscopes they cannot be clearly discerned. But

INFUSORIA AND ALGvE„ 11

teres t the intelligent reader in the subject, and we
will at once proceed to a more detailed history
of the peculiarities of Infusoria ; premising that
one family, the Desmidiece , which was by Ehren-
berg considered as belonging to the animal king-
dom, has, after much variety of opinion by natu-
ralists, been placed amongst vegetables, and con-
sidered as minute forms of Sea-weeds ( Aigce ) :
these will be described slightly in the sequel.

After the first expense in the purchase of a
good microscope, amusement may be constantly
obtained at all seasons of the year, without any
trouble but that of procuring and selecting water
likely to contain animalcules, and they are mira-
culously abundant everywhere. Many people are
disgusted after viewing water through a micro-

12 DROPS OE WATER.

scope, and suppose that all water abounds in living
creatures, and that, consequently, we drink them
in myriads. This is an error : there are none, or
very few, in spring water, and, as no one would
think of drinking from a ditch, or stagnant
pool, where plants abound, there is little to fear.
If necessitated to partake of water abounding in
life, the person is either ignorant of its state, or
the want is so urgent that the thought does
not occur ; and even should it arise, these deli-
cate transparent little atoms would not be per-
ceived by the taste ; — this fear or disgust may
therefore be dismissed. Many waters abound in
the larvse of gnats and other insects, and minute
creatures of the crustaceous order, but these can
generally be seen by the naked eye.

LOCALITIES. 13

In all parts of the world, and in most waters
where aquatic plants in a healthy state abound,
these invisible creatures may be met with, and
not only in stagnant pools, but in running
streams, and the broad ocean. Among water-
plants these little beings find shelter and food ;

4

therefore, when water is brought from these
localities, some of the vegetation peculiar to the
pool, or stream, should be procured at the same
time. They swarm amongst duckweed {Lenina) .
Many are found also in clear shallow pools, par-
ticularly in the spring. When a pond is ob-
served to have a stratum of dust on the sur-
face, or a thin film, it will generally be found
almost entirely composed of living creatures.
This dust-like appearance consists nearly exclu-

c

14 DROPS OP WATER.

sively of species of the most beautiful colours,
such as Pandorina , Gonium, &c. A shining film
of various colours is also occasionally seen on
standing water : this is composed of Infusoria ; a
red appearance being often given to water by some
species, and by others a yellowish hue. Sheets
of water often assume an intense green, from the
presence of many of these minute bodies. Lakes
have been known to change their colour very
mysteriously, and to have caused some alarm in
the superstitious ; but it is now known to arise
from Infusoria, as they are attracted to the sur-
face by the sun in the middle of the day,
and descend as that luminary declines ;■ — thus the
lake will be clear, morning and evening, and
turbid, or of different colours, in the course of

REPRODUCTION. 15

the day. If stalks of flowers are steeped for
a few days in water, it will be found to swarm
with life ; even a few dead leaves, or a bit of dry
hay, will produce the same effect. At first monads
will appear ; these will be succeeded by specimens
of the genera Paramecium , Amoeba , and those of
the class Rotatoria . I have tried these experiments,
and always with success. If the infusion be
kept a few weeks (particularly that formed with
leaves), one peculiar kind of animalcule will swarm
to a most astonishing degree, so that a drop will
contain hundreds, so close together that they form
quite a crowd, and yet all are in a state of activity,
and feeding from the vegetable matter disengaged
from the decaying leaves. They are not even con-
fined to these localities, for lakes and rivers, the

16 DROPS OP WATER.

fluids found in animals and vegetables, strong-
acids, and also the briny ocean, are full of these in-
teresting creatures. One kind of phosphorescence,
(an appearance which is so often observed by
the sea-side and at sea,) is occasioned by some
species ; and when we remember that this lumi-
nosity often extends for miles, we are lost in
j astonishment at the immensity of their numbers.

And here I may mention the evident use of
these wonderful beings. They appear wherever
decaying animal or vegetable substances are
found in water, and are extremely useful in de-
stroying what would otherwise taint the air with
noxious gases and smells. Minute algae also
assist in preserving the purity of the water in
which they live ; they serve as food, also, to

IMPORTANCE IN CREATION. 17

animals higher in the scale of creation than them-
selves. Captain Sir James Ross, in his Antarctic
Voyage, speaking of a small fish found by him in
the South Seas, and stating by what means it
and many others are fed, says, “ All are even-
tually nourished and sustained by the minute
infusorial animalcules, which we find filling the
ocean with an inconceivable multitude of the
minutest forms of organic life.” We may infer
from this, the immense importance of the Infuso-
ria in the scale of existence, for although only re-
motely supporting the higher animals, yet the
want of them would be greatly felt. Ehrenberg*
states, that a single drop of water may hold five

* A celebrated Prussian naturalist, who bas devoted his life to the mi-
croscopic investigation of animalcules and other minute objects.

c 3

18 DEOPS OF WATER.

hundred millions of the smallest animalcules.
What, then, can be the population of a lake, or
of the ocean !

I have watched specimens of the genera Flos -
cularia , Vorticella , and Stent or, for hours at a
time, and they have never ceased to feed on mi-
nute portions of animal and vegetable substances,
brought to them by the current they are enabled
to make in the water ; others eagerly pursue their
prey, or feed on the decaying vegetable matter
floating about : indeed, the appetite of these little
creatures seems insatiable. Many genera have
a strong chewing apparatus, like a mouth armed
with teeth. All seem employed in the same
way, though using different methods : — much
decaying matter must thus be taken away by

ACTIVITY OF HABITS. 19

this insatiable, though miniature army, provided
for the purpose. They, in their turn, afford
sustenance to aquatic insects, which are again
preyed on by fishes ; and thus food is prepared
for more highly organized animals, and lastly
for man.

Animalcules have never been observed to rest, or
at least to sleep ; but this may be partly owing to
the light necessarily used in viewing them, which
forms an artificial sun-light, exciting their powers
of motion : they may rest during darkness, when
they cannot be seen by us. Many are only at-
tracted to the surface of the water by the light
of the sun, and are difficult to be obtained on a
dull day ; they are, however, not much affected
by cold or heat, for they are procurable in winter

20 DROPS OP WATER.

as in summer, though not in such profusion :
they are found even under thick ice, and I have
frequently broken, in severe frost, the frozen sur-
face of a pond, and, inserting a bottle, have ob-
tained some most interesting kinds. Many of
the Polygastrica will bear a great degree of cold,
even more so than those of the class Uotatoria ,
whose organization is of a higher order.

It has, I believe, been generally observed, that
the more simple the organization of animals, the
more retentive is the creature of life, and this is
the case with these minute beings. The Botifer
vulgaris will even bear revivification several times.
Dr. Carpenter relates that he tried the experi-
ment six times with twelve specimens, and each
time some were perfectly restored to animation.

TENACITY OE LIFE. 21

By allowing the drop of water which held them
to evaporate, and at the end of twenty-four hours
giving them a fresh supply, he succeeded six
times in restoring some of them : at last two
only were left, and these unfortunately he lost.
Ehrenberg affirms, that if thoroughly desiccated
they cannot revive, but that they may remain in
a lethargic condition if deprived of water for a
certain time only. The same naturalist observes
that when an animalcule is frozen with the
water, it is surrounded by an exceedingly small
portion which is unfrozen, occasioned probably
by the animal heat of its body; but, should
the cold be so great as to freeze this, the crea-
ture dies. Animal heat in such an atom ! how
marvellous ! Yet they will bear a great degree

X £

22

DROPS OP WATER.

of heat also. The same naturalist says, that the
Polygastrica will bear the temperature gradually
raised to 120° of Fahrenheit, and some even
to 200°, but if raised suddenly they die at 140°.
Now, if we consider that water raised to 212° is
boiling, we shall be as much astonished at their
powers of enduring heat, as cold. Sir James
Ross, in his Antarctic Expedition, found upwards
of seventy species of Polygastrica with loricte, or
siliceous shells, in fragments of ice.

It will, therefore, be seen, that animalcules are
obtainable at all seasons, and in every place
where there are ponds or pools of water ; or
they may be procured from water-butts, or by
placing leaves, hay, or almost any vegetable sub-
stance in a little water, which has been previ-

VARIETY OE FORM. 23

ously found to have nothing living in it. It has,
therefore, been proved, that after the first ex-
pense in the cost of a good microscope, and with
proper care, so that no repairs are required, the
amusement is cheaper than most others ; never
ending, and never failing in interest.

A few particulars of the formation, and pecu-
liarities of structure, of these wonderful atoms,
will now be entered upon.

In the first place, the variety of form is most
astonishing, and strikes the observer perhaps
more than any other peculiarity. They are of
all imaginable shapes, and may be likened to
many objects with which we are familiar, — as
tops, trumpets, pincushions with pins in ready
for use, telescopes, balls, leaves, sticks, threads,

24 DROPS OP WATER.

bells, hollow spheres, &c. ; there are also others
like different kinds of fruit, flowers, fish, eels,
and serpents ; others, again, are egg-shaped,
round, square, three-cornered, oval, spiral, spindle-
shaped, star-shaped; besides some representing
funnels, cylinders, flasks, and many having an
apparatus which perfectly resembles a rapidly-
turning wheel. Most of these forms will be
noticed hereafter, when the genera and species
are more minutely described.

Animalcules have either a soft naked body,
or are covered with a kind of siliceous shell, or
horny case, which is transparent, and varies much
in form ; in some instances nearly covering the

* cc In some cases it is composed entirely of silica ; in others, of lime,
with a portion of oxide of iron Pritchard.

MUSCULAR POWER.

25.

body, in others only forming a shield. This
shell is called a lorica , and the term loricated
is used to point out the species having a shell.
None are supposed to have internal bones, but
their muscles must be of the most complicated
construction, to enable them to move easily and
rapidly, which many of them do in an astonish-
ing degree. One species ( Vorticella convallaria )
is attached to leaves and stalks, by a transparent
thread of some length : this it has the power of
suddenly contracting when danger threatens, so
that the body is instantaneously removed to a
distance. The muscles in this thread-like stalk
are so contrived, that it assumes on these occa-
sions a corkscrew or spiral form, and this action
brings the body close to the leaf on which it is

D

26 DROPS OF WATER.

fixed ; after the lapse of an instant the creature
gradually uncoils its stem, and is again employed
in procuring food. The muscle that produces
this motion (so rapid that it cannot be followed
by the eye) is seen within the stalk, with a glass
having the power of 250 diameters. There are
many equally wonderful displays of muscular
power to the one here described.

An eye, which is generally of a red colour, is
very visible in some genera, but not to be dis-
cerned in others, and probably they are destitute
of that organ. By some naturalists it is doubted
whether these spots are eyes ; but, as animalcules
are evidently excited by light, it is more than
probable : most of the Rotatoria possess them,
some species even having three, and one genus

ORGANS OF LOCOMOTION. 27

having seven or eight, on each side of the head ;
but they are less frequent in the first class,
though, even there, many species have two and
others one. How astonishing that so compli-
cated a structure as the eye should exist in so
very diminutive a creature !

Their organs of locomotion, or means of
moving through the water, are as varied as their
forms. The simplest method is by the aid of a
proboscis, which seems to be useful both in ob-
taining food and in giving motion to the body,
the creature using it as a kind of paddle, or oar ;
in some species there are two of these members.
Others, again, have many short ones (called cilia)
surrounding what may be termed the mouth,
and by which they not only bring food to that

28 DEOPS OF WATEE.

|

orifice by their rapid movement, which creates a
current in the water, but the same action propels
the body with wonderful speed, so that the eye
can scarcely follow it. These cilia, when in mo-
tion, have the appearance, to the eye of the spec-
tator, of a rapidly -revolving wheel, and this ex-
traordinary effect is produced in the following
way. — Each of these little thread-like members
has a rotatory motion, the point describing part
of a large circle, and the base (which is seated
on a bulb) part of a small one ; this motion, when
all are seen in action at once, gives the appear-
ance of a turning wheel, because the apparent

| revolution of the whole takes place in the same
time as the real rotation of a single one. I
know nothing more wonderful than this forma- j

ORGANS OF LOCOMOTION. 29

tion, and, indeed, it is one of the most interesting
spectacles that can be observed by the aid of the
microscope. It is supposed by some naturalists
to be also the means of respiration. In some
genera the cilia are not confined to the opening,
but cover the whole body, and by this means
they progress rapidly through the water, having
a revolving motion, like that of a ball. Some
have a gliding movement, similar to the snail
or leech ; others, again, have a foot, with which
they catch hold of substances that come in
their way. In many species, also, bristles
are attached to the surface of the body,
which may act as fins ; and some kinds have
appendages, curved at their extremities, and
serving as hooks to attach the animal to sub-

30 DROPS OF WATER.

j

stances on which it feeds. Some few are mo-
tionless, others revolve on the centre, or move by

| leaps, or undulations ; and, in fact, they seem to
use every kind of motion that can be conceived.
Infusoria increase more rapidly than other
organized beings. In some of the modes of
reproduction they resemble animals of a higher
order of creation. Very many species lay eggs,
which they attach to water-plants ; others pro-
duce their young alive ; but many increase by
germs, or buds, growing from their own body,
which are separated when sufficiently arrived at
maturity ; others, again, divide into two or
more parts, and each becomes a new animalcule
with equal powers. But, perhaps, the most ex-
traordinary is the compound formation of the

MODES OF REPRODUCTION . 31

| Volvocina family, in wlych many individuals
are enclosed in a transparent globe, where
they have increased by self-division : as they
grow in size the case enlarges also, but con-
tinues entire till they have arrived at maturity,
when it bursts, and the inhabitants, as they may
be called, are set at liberty, each forming in its
turn a new globe, and again increasing by self-
division. How wonderful are all these peculiari-
ties in beings unseen by the naked eye ! These
facts must create an eager desire to witness these
marvellous atoms ourselves ; and those who have

a taste for investigation in natural history, will

j

here find ample scope for amusement.

It was formerly supposed that animalcules re-
ceived their nourishment by absorption through

32 DROPS OP WATER.

the skin, as in many kinds mouths could not be
discovered ; but by feeding them on coloured
substances, an internal structure has been ob-
served equally complicated with that of larger
animals, and consisting of muscular and nervous
systems, all wonderfully suited to them respective
wants. As these creatures are for the most part
transparent, the being enabled to feed them on
coloured substances, such as indigo, sap-green,
and carmine, has given naturalists the power of
investigating the internal construction, which
would have been impossible without this plan.
The method is to place a very small portion of
the carmine, well rubbed down with a little
water, in a drop containing animalcules; they
will immediately appear very active, and in a

CARMINE, ETC., AS E00D. 33

few seconds the internal sacs will be filled with
red colour, whilst the rest of the body will re-
tain its original appearance. The cilia, probosci-
des, and other appendages will also be much more
clearly perceived than without the assistance of
the foreign substance. This experiment requires
some nicety and care, and the new diet does not
seem to injure the animalcules, for, as indigo* and
sap-green are vegetable, and carmine is an animal
production, they probably do not find them dis-
agreeable; but no metallic substance must be used.

It is a wonderful fact, that a drop of water
exhibiting to the eye only a few particles of ve-
getation and sand, may, by the aid of a glass,
be found to contain a crowd of animated be-
ings, all beautifully and curiously constructed,

34 DROPS OF WATER.

all enjoying life, and providing for their various
wants — their beauty so great, that we can
scarcely bear to lose sight of them by with-
drawing the eye from the microscope; and
yet that drop is as nothing in the scale of
creation, and we wipe it away with hardly a
thought of what it contains, intent on viewing
fresh wonders in the next drop we may take
up. The educated mind, however, knows that
nothing is made in vain, and that even the
minute beings under observation have had
their influence in maintaining the purity of
the water and atmosphere, and thus spreading
around, benefits of which the uninstructed are
perfectly ignorant.

This introduction will be concluded by a short

FOSSIL INFUSORIA. 35

account of fossil Infusoria. A fossil animalcule !
Is it possible that such minute and delicate
bodies can be changed into, and preserved as,
fossils ? This is really the case, and the following
extracts will prove the truth of this remark.—

Ehrenberg says, “ The Infusoria, in conse-
quence of their siliceous shells ( loricce ), form in-
destructible earths, stone, and rocky masses.
With lime and soda we can prepare glass out
of invisible animalcules, use them as flints, pro-
bably prepare iron from them, and use the
mountain-meal, composed of them, as food in
hunger/’

To prove this marvellous fact, the following
interesting extracts are drawn from Pritchard’s
‘ History of Infusoria ’ : — -

36 DEOPS OP WATEE.

“ The shell-like coverings ( loricce ) are found in
large masses, covering many miles of the earth’s
surface, and occur, when indurated and mixed
with argillaceous and other earths, in the form
of siliceous rock, slate, &c. These remains of
the primeval inhabitants of our globe are re-
cords in the pages of history, penned by Infinite
Truth, unbiassed by ignorance and prejudice ;
and form some of the first-fruits of the effective
application of achromatic glasses in our micro-
scopes.” “It is hardly possible to take up and
examine a dozen flints without discovering spe-
cies of Infusoria enclosed within them. These
may be seen under the microscope, when very
thin sections are made.”

As flint is used, in the manufacture of glass,

FOSSIL INFUSORIA. 37

the shells of these creatures are thus found
coming into use, after the inhabitant has .been
dead thousands of years. Dr. Mantell remarks,
in his £ Thoughts on a Pebble/ — Investigation
has shown that a great proportion of the mass
of the (flinty) pebble, is actually composed of the
aggregated fossil skeletons of animalcules, so mi-
nute as to elude our unassisted vision, but which
the magic power of the microscope reveals to us,
preserved, like flies in amber, in all their original
sharpness of outline and delicacy of structure.5'

An extract from another author will prove that
chalk abounds also in remains of Infusoria. —
“ Throughout the chalk beds there are layers of
flint, — that is, masses of silex, dr flint, of various
sizes, from a pea to a man's head, each lying

E

38 DROPS OF WATER.

detached amidst the chalk. Whence this great
quantity of a substance, which seems to be charac-
teristic of the chalk formation ? The supposition
is, that it has been derived mainly from siliceous
coverings of animalcules ! The remains of many
of these minute and humble animals have been
discovered in the chalk, some of them being the
first animals which yet exist in the species upon
earth. It has also been found that the flints
invariably include the remains of some sponge,
or other humble animal form, the lineaments of
which are often beautifully preserved amidst the
dark glassy substance, and may be detected by
a microscope, if not by the naked eye. Now, if
the silex from the coverings of the dead Infu-
soria, were in solution amidst the settling sub-

FOSSIL INFUSORIA. 39

stance of the chalk, any decaying sponges, Al-
cyonia , sea-urchins, or other animals placed
there, would be sure to collect the particles of
the silex around them, and thus be converted
into flints.” * * * “We refer to beds of

greater or less thickness, composed exclusively
of the solid remains of animalcules — creatures
individually so small, that only a microscope
could enable human eyes to see them. Such a
rock (called Tripoli) is found at Bilin, in Bohe-
mia,* and at Planitz, in Saxony. It has been
used as a powder in some of the arts, for ages,
without any suspicion of its being thus composed.
But within the last few years M. Ehrenberg, a

* The series of strata forming this polishing slate is about fourteen
feet thick.

I 40 DROPS OF WATER.

scientific Prussian, has fully ascertained that it
consists simply and wholly of the siliceous cover-
ings of certain minute creatures, some of which
belonged to species still to be found in stagnant
water. To common perception, the powder of
; which the rock may be said to consist resembles
flour- and in Norway, where it is called Berg-
mehl (that is, mountain meal), it is actually used
in times of famine as food ; for which it is not
entirely unsuitable, seeing that there is always a
per-centage of animal matter left in it, in addi-
tion to the siliceous shields.* So extremely
small are the creatures of which these rocks
form the sepulchre, that, according to M. Ehren-

* Dr. Carpenter says, this earth contains a large proportion of animal
matter, — about 80 per cent, of its weight.

FOSSIL FLOUR. 41

berg’s calculation, ten millions of millions of
individuals might be required to fill the space of
a cubic inch. Yet in the smallest of these crea-
tures there have been found several stomachs,
besides other organs ; and minute as the cover-
ings are, they are variously sculptured or marked,
so as to form distinctions of species.”

Here may be added, also, the remarks of other
authors on this curious subject. — “In Swedish
Lapland, under a bed of decayed mosses, forty
miles from Degesfors, in Umea Lapmark, is
found a stratum of this substance known there
by the name of Bergmehl. When examined by
the aid of the microscope, it is found to consist
almost entirely of the remains of minute or-
ganisms. In seasons of scarcity this is made

42 DROPS OF WATER.

use of in certain quantities mixed with flour in
the manufacture of bread by the poor : not that
it contains any nutriment (or, at all events, it pos-
sesses it in so small a quantity, as not to be able
alone to support life), but on account of its serv-
ing to distend the stomach, and thus to prevent
the unpleasant sensations attendant on an im-
perfectly-filled state of that organ.” This sub-
stance seems also to be occasionally used in
China, as is shown by the following statement
published in 1839 by M. Laribe, a missionary : —
“This earth is only used in seasons of great
dearth. One of our Christians, who, at the
period of the last famine, fed upon this substance,
with five other individuals composing his family,
informed me, that when they made use of it,

FOSSIL FLOUR. 43

; —

| they bruised it into a very fine powder, mixing

three parts with two of rice-powder, or, better,
the flour of wheat, to make small cakes, which
were seasoned with salt or sugar. Recourse was
only had to this in times of great want ; and that
being over, no one ever dreamed of making use
of it as an article of food. Those persons who
employed the fossil flour without mixing it with
vegetable meal, scarcely ever escaped death/7
“ This mountain meal is principally composed of
the flinty coverings of the Navicula viridis, Gal -
lionella sulcata , and Gomphonema gemmatum , all
of which are to be found in a living state/5
Dr. Carpenter, in his interesting work entitled
‘Principles of Physiology,5 whilst speaking of
fossil animalcules, says, “ It is peculiarly inter-

44

DROPS OF WATER.

1

esting to trace such occurrences in progress at
the present time. The author has seen water,
brought from a lake in the island of St. Vincent,
crowded with the shields of races of Naviculce
which at present inhabit it ; and the mud
which is being deposited in abundance at the
bottom of the lake, is almost entirely composed
of them.”

There can be few subjects more interesting
to the thinking mind than these details of the
living animalcule, and its fossil remains.

“ These viewless beings, to whom
Each tiny drop is as an ample world, each day
A life of ecstasy, fulfil their Maker’s high behests,

And, in obeying, find felicity.”

An outline of the history, habits, and loca-

CLASSIFICATION. 45

lities having now been given, an investigation
of the scientific classification, and more lengthy
details of the most interesting genera and species,
will follow; the reader or student will then be
enabled to understand the more learned works of
Ehrenberg and Pritchard, whose volumes are
so often quoted, and to whom these pages are
indebted for many of the descriptions.

The object of this little book is not to treat scien-
tifically of the minute forms mentioned, but only
to induce the lover of nature to search into their
curious history, and also to prepare the student
for more learned works ; the classification will
not, therefore, be entered upon minutely — a short
account only of the great classes into which they

are divided will be sufficient. But it must first

I

46 DROPS OF WATER.

be stated, that naturalists have some difficulty, in
many cases, in determining whether the minute
object under examination belongs to the animal
or vegetable world. This appears very extraor-
dinary, but when the following details have been
read, and it is found that what seemed to be a
plant, has within it certain granules which, when
discharged, act like living beings, swimming
about, having all the movements of animals, yet
at last fixing themselves to a substance, and
after a time assuming the appearance again of
vegetation, it will be acknowledged that the sub-
ject is one of extreme difficulty. Professor Ryrner
Jones remarks, that the physiologist has many
difficulties, “ who endeavours to draw the boundary
between these two great kingdoms of nature ; for

CON EERY M.

so gradually and imperceptibly do their confines
blend, that it is at present utterly out of his
power to define exactly where vegetable exist-
ence ceases, and animal life begins.”

In some of the fresh-water Conferva which
form the green slimy patches seen in ponds, the
reproductive organs are the little green grains
filling the transparent tubes of which the plant
is composed. These, when ripe, leave the tubes,
and have a very visible, and voluntary movement
in the water, so like animal life, that they have
in that state been taken for animalcules. But
the Conferva comoides , growing on the coasts
of Picardy and Normandy, and mentioned in a
work entitled 4 Observations sur les Limites qui
separent le regne vegetal du regne animal/ is of

48 DROPS OF WATER.

a very remarkable construction, and peculiarly
interesting, proving how nearly connected are the
two great classes of animals and vegetables. This
little plant-like substance is seen at low water,
attached to stones, and is in the form of a hair
pencil, from half an inch to an inch in length,
each thread being finer than a hair, and slightly
branched, rounded and compressed : they contain
a number of small yellowish bodies, which are
first round, then oblong, afterwards more pointed
at one end, which becomes transparent. They are
packed very closely, but when the cell bursts,
they move about in the water in the most amus-
ing manner, and keep up a voluntary, incessant
motion for a considerable time. They at last
fall down in immense numbers on the stones, and

ULViE. 49

emit a globule of particles which is supposed
to be their fry. This substance lengthens, and
branches, and again forms long hair-like threads,
similar to those from which it sprang. In the
green ditch-laver (JJlva bullata , or minima ), by
the aid of the microscope, may be seen a num-
ber of green granules, — these, when separate
and loose in the water, have a rapid movement,
as if chasing each other. In time, two ap-
proach, and touch one another, then retreat, touch,
and retreat again ; then four combine to execute
the same movement ; and at last, the whole party
thus grouped in fours, dance together in seeming
confusion. After a time the motion ceases, and
they form the new substance known as TJlva *

* Lindley’s Botany.

50 DROPS OP WATER.

It will be easily imagined, therefore, from
this marvellous account, how difficult it must
have been to classify and arrange these little
atoms, and, consequently, naturalists have differed
greatly on the subject. The microscopist will
be greatly struck with many minute green ob-
jects, of exquisite form, which will be seen lying

j

quietly at the bottom of the water, having no
movement, but greatly resembling a seed, or pod.
These have been, and still are by some naturalists,
supposed to be of an animal nature, from the
movement of the granules contained in their sub-
stance, but by late writers they are considered
vegetables. They will, however, be inserted here,
not only from the interest they excite, but from
their frequent occurrence in water in which ani-

CLASSIFICATION. 51

malcules abound, so that the student may not be
at a loss as to their nature when they are met with.

Infusoria are comprised under two great classes,
Polyc/astrica and Rotatoria ; the former being dis-
tinguished by appearing to have numerous vessels,
or stomachs, for carrying on digestion, and the
latter having but one. This is Ehrenberg's
method of classifying them ; and though Meyen
and others think the vessels of the first class are
not stomachs, the name must be retained until
the fact is ascertained.

After some experience in viewing animalcules
with a glass, them general form and outward
appearance is sufficient to enable the observer to
determine in which class to place them. The
Rotatoria have usually a foot near the extremity

I 52 DROPS OP WATER.

of the body, and rotatory organs affixed to the
head : these, and their higher organization, render
them in general distinguishable from the Poly-
gastrica . Each of these classes is divided into
many families, genera, and species, the different
kinds amounting to nearly eight hundred well-
ascertained species. This number will probably
increase, as our microscopes are improved, and
observers multiply. We can understand that
the labours of microscopists must have been very
great, when we consider the extreme difficulty of
watching these minute productions. It fre-
quently happens that a specimen is lost to view
after only a very slight inspection, and perhaps
another of the same kind is not met with again
for days or weeks. I cannot describe the regret

CLASSIFICATION. 53

I have felt when having to lose sight of a very
interesting specimen, perhaps new to me at the
time. After watching it for hours, a period must
come when the drop containing it will either eva-
porate, or an additional drop or two must be
mixed with it, and then the probability is that it
may never be seen again. If very small, and not
fixed to a leaf, this is most likely to happen. The
movements of many are also so rapid, and the
impossibility of touching them so great, that it
is only wonderful we have such correct and i
minute accounts of these atoms, which are so
completely invisible to the naked eye.

As these pages only aspire at being considered
an introduction to an interesting study, I shall
not enter on a scientific arrangement, further than

54 DROPS OF WATER.

that of describing the objects I select in regular
succession, according to Ehrenberg’s classifica-
tion, with the exception of the family Baciliaria,
which I place first, as the species are now consi-
dered (at least, the greater part of them) to belong
to the vegetable kingdom. I shall suppose four
drops of water to be under inspection at diffe-
rent times ; and though it seldom happens that
the objects I have depicted in each drop are found
alone at any period, still I have thought this plan
not an unnatural one, giving clearly some idea of
classification, and preparing the way for more
scientific works, when the subject is made a deeper
study. The specimens contained in the First Drop
are minute Algse, and other objects nearly allied
to them : they are found more particularly in

CONTENTS OE THE DROPS. 55

bog-water, and may be seen in great numbers
together. Those contained in the Second Drop
are polygastric, and are often found in prodigious
numbers in spring, to the exclusion of others.
The individuals of the family Vorticettina (also
Polygastricd) will nearly occupy the Third Drop ;
and their beauty is so great, that they fully attract
the attention when present in the field of the
microscope. The Fourth Drop will be occupied
by the class Botatoria. By this means some of
the most striking microscopical objects found in
water will have been examined.

DEOP L

I have mentioned in the introductory chapter,
that many of the microscopic objects found in
water are at present not sufficiently known, to
enable naturalists to determine, beyond dispute ,
whether they belong to the animal or vegetable
kingdom. Ehrenberg thinks, to the former be-
long all the genera I am about to describe in this
section. Dr. Meyen is of opinion that many of
these are decidedly vegetable ; and others imagine
that all may belong to the latter kingdom. By

MINUTE ALGJE. 57

botanists, some of them are placed among the
minute Algae ; and if colour and general outward
appearance alone are considered, connected with
the fact, that in most cases they are immoveable,
the young student will conclude that the botanist
is nearer the truth than those who argue for their
animal nature. Still, we must come to no hasty
conclusion, for if the learned differ on the subject
we must be content to wait for further informa-
tion; and it is not unlikely that these minute
and puzzling atoms may form the connecting
link between the two kingdoms. Ehrenberg
describes them as polygastric, the body having
variable processes, and being covered by a lorica ,
or shell ; as undergoing self-division, but most
of them being connected together by a thread.

58 DROPS OF WATER.

forming chains, or rounded groups. This im-
perfect division is similar to that described in the
family Vibrionia , amongst animalcules. These
facts caused Ehrenberg to conclude, after patient
investigation, that they belong to the animal
kingdom. Dr. Meyen, on the contrary, argues
for their vegetable nature. The want of actual
motion in most of them, is a great point in favour
of his opinion ; and, regarding the self- division,
he affirms that it is very common in the lowest
plants, as well as in some of the organs of the
higher kinds. The green corpuscles seen within
the Desmidiea are similar to those found in the
cells of the Conferva , though Ehrenberg con-
siders them as eggs. This group, therefore, may
with great reason be looked upon as belonging

MINUTE ALGAE. 59

to the vegetable kingdom;* but another portion,
termed the true Bacillarice , and named Navicu -
lace a, after the most interesting genus, have a
greater resemblance to animal life, much more
spontaneous movement, and currents are also fre-
quently observed on the sides, as if minute cilia
existed ; still Dr. Meyen classes even these with
plants, and observes that they are by no means
so free and active as the spores of the Algse,
Notwithstanding some uncertainty respecting the
true nature of this family, it is very interesting,
and some species are possessed of great beauty.

* Mr. Ralfs’s able work on British. Desmidiese appears to set the subject
at rest, as regards this section of the family Bacillaria ; for he parti-
cularly mentions that the presence of starch (peculiarly a vegetable pro-
duction) may be detected in the atoms composing it, by the application
of tincture of iodine , which turns them of a violet or blue colour.

60 DROPS OF WATER.

The first section, the Desmidiece , are a family
of microscopic Algae, distinguished, like most
other plants, by their green colour ; they are
formed of vessels or cells containing a green sub-
stance. These cells, or joints, separate either com-
pletely or only partially, some genera forming
long filaments, by the union of many cells, and
others are seen generally only in pairs. I shall
describe a few of the most singular in appear-
ance, and those most commonly found.

The genus Desmidium is seen as a long, pale
green filament, formed of many cells. There
are two species. Desmidium Swartzii (Plate I.
fig. 1) has three edges, forming a triangle
when viewed transversely ; when many cells are
connected together, and the filament is lying

MICEASTERIAS. 61

longitudinally under the eye of the observer, a
dark line is seen to cross alternately from one side .
to the other — this is caused by the twisted form
of the filament, and the line is the third corner of
the triangle. It separates into single joints or
cells, and then shows its triangular shape, with the
green substance within forming a star of three
points. This is a species of common occurrence.
Besmidium cjuadranguiatum is more rare, and
only seems to differ from the last in the number
of sides. There are other genera of these thread-
like Algse, but this is the most striking.

The genus Micrasterias contains many sin-
gular forms ; they are more or less round, and
flat, deeply divided into two lobed segments, or
cells, and notched or cleft at the edges, some-

Cr

62 DROPS OF WATER.

times even rayed ; tlie colour is green, but with
the edges or rays transparent, forming beautiful
objects for the microscope. They will be viewed
with great interest, and are so large as to be visi-
ble to the eye without the aid of a glass, but only
as a small green dot. The mode of increase is
very remarkable : — the two segments are united
by a narrow band or tube, and this produces
two new minute segments, which gradually in-
crease, and separate the two original portions ;
the young acquire colour, and soon look like the
old ones ; then the latter are entirely separated,
each taking one of the newer formations with it.
This singular process is constantly being repeated.
Micrasterias denticulata (Drop I. fig. 2) is one
S of the most common found in bog- water : it is

EUASTRUM. , 63

very prettily denticulated at tlie margin, besides
the deeper divisions ; and the white edge, and
bright green centre, are strikingly beautiful.
M. crenata is smaller, and less denticulated.
M. rotata is large, and with two of the divisions
cut in a curved line. There are several other
species, but they are rare.

Euastrum somewhat resembles the last genus,
but the species are more oblong in form, and
have circular protuberances on the surface. They
are attractive, also, from their size. Euastrum
oblongum (Drop I. fig. 3) is common in pools : the
form of it is much longer than broad, with five
or six prominences. Euastrum insigne is smaller,
has the segments inflated at the base, and taper-
ing into the form of a neck, with the end a little

64 DROPS OP WATER.

dilated ; the prominences are arranged two on
each segment. There are more than a dozen
species of this genus known.

In the genus Cosmarium the segments are
more or less round, and neither dentated nor
rayed at the edge. Cosmarium margaritiferum
(Drop I. fig. 4) is rather abundant ; there are
more than thirty species known.

Xanthidium greatly resembles the last, but is
armed with spines, and has a circular projection
near the centre of each segment. Xanthidium
armatum (Drop I. fig. 5) has short thick spines,
placed in pairs round the edge of each segment,
each spine having several points, and occasionally
some scattered on the disc. This species is often
found in masses, floating in the water of shallow

STAURASTRUM. 65

pools. Xanthidium aculeatum has the spines
simple, shaped like a horn, and numerous;
other species have them longer, and but few in
number.

The genus Arthrodesmus has the segments
entire, with a single spine on each side ; the
two segments, joined by a very narrow band,
are broader than long, and smooth. There are
often four united together. Arthrodesmus con -
vergens (Drop I. fig. 6) has the spines of its seg-
ments curved towards each other. A. incus has
the spines diverging outwardly, and the ends
truncated.

The genus Staurastrum has a great variety of
species, amounting to about forty. They are
mostly of minute size, and differ but slightly at

66 DROPS OF WATER.

first view from the last genus. The segments
are broader than long, and in many species elon-
gated into a process. This is of a more angular
form than Arthrodesmus. 8. cuspidatum (Drop I.
fig. 7) will serve as an example.

Closterium is a very interesting and striking
genus. Many of the species are large, and all of
a deep green colour ; the form also is very grace-
ful, the two valves are elongated, narrow, curved,
and often of the form of a crescent, the union of
the two being marked in the middle by a pale
line, but there is no constriction there, as in the
former genera, and there are neither spines, nor
prominences of any kind. In some species there
are lighter green dots arranged down the length,
or scattered about, and in most may be perceived,

CLOSTERIUM. 67

near the ends, with a high magnifying power,
a transparent spot, containing minute granules
in constant motion. Some species are smooth,
others striated — but this is rarely seen, excepting
when the case is emptied of its green matter.
The method of increase is very similar to that
described in other genera, but differs in some
degree. The pale line in the centre becomes
double, the intermediate portion gradually in-
creases, and then another transverse line becomes
visible in its centre ; when mature, complete
separation takes place there, and two Closteria
are formed. The species are above twenty.
C. acerosum (Drop I. fig. 8) is a very pretty
object, bright green, and very slender in form ;
C. moniliferum rather crescent-shaped, with a

68 DROPS OP WATER.

line of transparent dots down the middle ;
C. Diana (Drop I. fig. 9) is quite crescent-
shaped, small and slender ; C. setaceum (Drop I,
fig. 10) is perhaps the most beautiful — it is
very slender in the centre, the ends tapering
into long beaks, and rather curved, which give
it an elegant form. These specimens will be
sufficient to make the reader or microscopist
familiar with the genus.

Spirotania greatly resembles Closterium in
size and general form, but is easily distinguished
by the green matter forming a spiral line from
one extremity to the other ; there is no mark of
division in the centre, and the ends are round.

Occasionally may be seen very minute bun-
dles of green objects, like little faggots ; — these

PEDIASTTLTJM.

69

| belong to the genus AnMstrodesmus , and there is
but one species, falcatus.

The next genus, Pediastrum , is composed of
many species, all being more or less like a star ;
they are formed of several little cells, four or
more united together either in a single or double
circle : they are very curious, and soon attract
notice. I shall only give two species, which I
have myself seen repeatedly — P.joertusum (Drop I.
fig. 11) and P. Napoleonis (Drop I. fig. 12) : the
figures show their extraordinary forms more
clearly than any words.

Scenedesmus comprises little objects composed
of from two to ten minute cells, arranged in a
row, instead of in a circle, as in the last genus.
S. quadricaudata (Drop I. fig. 13) is common.

70 DEOPS OF WATER.

This slight sketch of the Desmidiece will suffice
to call the attention to an interesting and won-
derful family of minute objects, only discernible
by the microscope, and therefore unknown to
the greater number even of those who interest
themselves in botany. If this brief account
should excite the curiosity of the lovers of nature
to make deeper researches, the valuable work by
Mr. Ralfs is recommended as the most useful to
assist the student ; — much information has been
derived from it for these pages.

Naviculacea. — I shall not again repeat the
opinions of naturalists, or the disputes as to the
nature of this branch of the family Bacillaria,
but merely name the most interesting of the
genera. Navicula is so called from its shape, all

NAVICULA. 71

the individuals being more or less in the form of
a little boat, — and their quiet gliding motion
increases the resemblance. The bright colours,
or delicate transparent appearance of the lorica,
make these little objects also very attractive ;
and I have watched a number of them moving
in different directions with great pleasure, for
their pace is so slow and gentle that all their
habits may be noted. They appear to me to
have decidedly a will of their own, and to avoid
dangers or obstacles in their path, just as many
of those animalcules do which are decidedly con-
sidered as belonging to the animal kingdom ; and
yet, as Dr. Meyen says they are by no means so
free and active as the spores of the Algse, we are
again puzzled. When watched with attention,

72 DROPS OP WATER.

they are found to glide .slowly along at the
bottom of the water, in a straight line, though oc-
casionally a little slightly zigzag, as if to avoid
the roughness of the glass ; then, when anything
obstructs their path, they do not go round it, but
immediately turn back on almost the same track,
without turning the body, and this motion I
have seen a specimen keep up for some time : a
little tap on the glass will arrest their progress,
and then they immediately reverse their motion.
When, however, they meet with a substance which
may afford them food, they stop, and either glide
under or about it. They appear to have cilia
at the sides, for I have often observed small sub-
stances propelled along the body of the creature,
and even running backwards and forwards several

NAVICULA. 78

times, as if the Navicula might be extracting
food from it. I do not know a prettier sight
for the observer, than a drop of water containing
several of these cnrions little creatures of dif-
ferent colours and shapes, gliding in various di-
rections, and all actively engaged in their pur-
suits. Ehrenberg describes about forty species,
some found in salt water, some in fresh, and
others fossil. They are seen single, and in pairs,
but never in chains, or bands, like the rest of
this division of the family. They are generally
broader in the middle than at the ends : some
have the two ends very sharp, others are more
blunt, and one or two are more round than long ;
a few have the ends curved different ways. Some
are green, some brown or red, and others almost

H

74 DROPS OP WATER.

transparent ; a few, also, are of a golden yellow.
N. viridis (Drop I. fig. 14), N. amphisbvena (fig.
15), and N. acus (fig. 16), are frequently seen.

The genus Bacillaria, from which the family
derives its name, is composed of bodies of sin-
gular construction. They seem originally to form
connected lines, but, when mature, separate gene-
rally only in part, forming zigzag chains : in this
state they move slightly, and one marine species,
B.paradoxa, when separated from its compa-
nions, moves quickly like a Navicula. B. vulgaris
(Drop I. fig. 17) is by many botanists looked
upon as a vegetable, and named Biatoma Jloccu -
losum : it is found both in fresh and salt water,
and has a straight lorica three or four times as
long as broad ; and when seen sideways it is in

FRAGILAEIA. 75

the form of a spindle. B . cuneata (Drop I.
fig. 18) is- of wonderful construction — each in-
dividual is wedge-shaped, and they still preserve
the straight ribbon or chain-like form, by being
placed alternately the broad and narrow end
together. These chains of the Bacillaria are free
and floating ; as well as those of the next genus,
Fragilaria , specimens of which are frequently
seen to rise in the water, and turn round ; the
individuals also, when separated, move forward
gently. They may be distinguished from Na-
vicula by being square at the ends, instead of
pointed, and having two openings instead of one.
In F. grandis there are as many as thirty indi-
viduals found linked together. F. rhabdosoma
(Drop I. fig. 19) is very slender, and the bands

76 DROPS OP WATER.

[ <

drop to pieces very easily, and then the individuals
creep about. The last genus of this division is
Meridion , the separate individuals of which are
wedge-shaped, but, unlike the Bacillaria cuneata
mentioned above, they are arranged with all the
small ends placed together, so that the band
is not straight, but forms a spiral, if many are
linked together; if there are but few, then a
circle, or part of a circle, may be formed : M.
vernale is the species usually seen. How mar-
vellous are all these variations, when we consider
the minute size of the objects !

The next section of the Bacillaria family is
called Bchinellea , and the genera are distin-
guished from those of the other divisions, by
being attached at one extremity to weeds, &c.

ECHINELLEA. 77

They may be seen of various forms, some single,
others in groups • some long and narrow, others
wedge-shaped, and occasionally they grow one
on the other. The individuals of one genus,
Gomphonema , form quite a little tree : each one
is wedge-shaped, and at certain periods becomes
detached, and creeps about, but it is not known
whether it forms another stalk ; it is found
attached to Lemna. Those of the genus Echinella
form a cluster like a fan, and this is caused by
the body dividing, but not the stalk, so that the
individuals, being wedge-shaped, as they lie side
by side, have a fan-like form. These are prin-
cipally found in the sea, attached to sea- weeds
and mollusca ; but two are found in fresh water.

The fourth section consists of curious little

78 DROPS OF WATER.

bodies, found principally in the sea, and too com-
plicated to admit of description here ; but I
must mention the genus Acineta , which has been
added to the Bacillarice. It may be frequently
noticed on the stalks of Lemna} and, being
extremely pretty, shall be described. The body
is affixed by a short stalk, is small, and round
or bell-shaped, with numerous rays project-
ing from it in various directions, each appear-
ing to have a slight knob at the end ; these
rays do not vibrate, but are said to be retractile.
This I have' not observed, for I never could trace
movement in any part of this singular little
being. It is nearly transparent, very small, and
may be almost compared to a pin-cushion with
pins in it ready for use, as the knobbed rays

ACINETA. 79

are of some length. In Acineta mystacina these
rays are arranged in two bundles ; in A. tuberosa
they are fewer in number. This little object
shows the amusing variety of forms found in
this minute portion of the creation ; and though
the specimens seen in this drop of water are some
of them of an uncertain character, they have yet
considerable beauty and interest, and will not
fail to reward the student who diligently searches
for them.

DROP II.

It has been remarked before, that the class
Polygastrica derives its name from the globular
vessels, seen through the transparent body of the
animalcule, being supposed to be numerous di-
gestive sacs.* In forty-eight species, eyes are
perceptible, and the colour is red, with the ex-
ception of one species, in which it is black. They
have no feet, but their locomotive organs con-
sist of vibratory cilia, which are in constant rapid

* The name is from two Greek words, signifying many stomachs.

[

lytoaas crepusculum. .

2. Doxococcus Tuber .

3. TracKelomona-s volvo cma.
4,. PatLcloriiLa morm.

5. G-onmm pecfeoial® _

6. S.ynpra ■

7. Eudoriaa ele.gaus .

8 . Yolvox glo b ato r .

13 : D^fflugis jroteii i

9 . Astasia .Aseraatoaes.

10 . Saglena ^gumea .
11. Dinotry.o-a sertulaTia .
12 . A.in.ee'ba prir.eep s .

JUerc. % WvcTbols, i>n/>

dtc£ £otJ>'-

.'JDIMSIP M.

1. Menas crepus eulum. .

2. Doxoeoccus ruber .

3. Trachelomonas -volvocina.

4. PaucLorma moim.

5. G-ordum. pectpxas|& .

6. Syttura rvell’a .

7. Eudorina elegaas . dd
S.Volvox gldbator .

13 Difflugia. proteif'ormis .

9 .• Astasia 'k^matoles,. :

10 .. Eaigdcna; Vnngvdr.ea .

11: Dmobryon sertularia. .
12. A nice "b a princ eps .

£zc.vc.

iC TV'icJl.O Is.

POLYGASTRICA. 81

motion, and by which they move in various ways,
some gliding slowly, others rapidly, some again
darting from place to place, and many having
a rolling motion : indeed, their modes of progres-
sion are almost as various as their forms. The
methods of reproduction are principally three : —
by eggs, which is the most common ; by self-
division of the body ; and by the growth of buds,
or gemmules, upon the parent. They increase at
a most rapid rate, by each of these methods. I
have watched the self-division frequently, and
more particularly in the Vorticella convallaria , as
that interesting animalcule is attached to weeds,
so that its movements can be noted with great
certainty. I shall describe the process when I I
more particularly mention that species. There j

82 DROPS OP WATER.

are as many genera loricated as illoricated in this
class. The Polygastrica are found in all parts of
the world, both in fresh and in salt water.

The first family into which this class is divided
is named Monadina , containing creatures of the
most minute forms, and only interesting to the
unscientific observer on that account; most of the
individuals requiring very patient investigation,
and high magnifying powers, before their move-
ments and habits can be sufficiently understood
to be minutely described. It has been discovered,
however, that some of the genera possess eyes, and
most of them cilia ; some only have a proboscis,
and others again a tail ; none are enclosed in a
lorica, and they increase by self- division into two
or four parts, each becoming a perfect individual.

MONAS. UVELLA. 83

The genus Monas is represented in Drop II. by
the species M. crepusculum (fig. 1), and is curious
as being the smallest of known living beings. It
feeds on decaying substances, and may be ob-
served in considerable numbers, as a minute co-
lourless speck, moving very rapidly, by the aid of
a proboscis, and enjoying its transitory life in the
society of its kind. Another species is of a deep
red, and abounds in salt-marshes on the shores of
the Mediterranean, to which it imparts a red co-
lour. The M. crepusculum cannot be seen without
the aid of a glass magnifying 300 diameters.

The individuals of the genus TJvella cluster
together so as to form a mass like a mulberry.
The species U. glaucoma is found in stagnant
water. Ehrenberg was able to see, within the

84 DEOPS OF WATER.

body of this minute creature, some green Monads
which it had eaten, and by which it was proved
not to be herbivorous. With a magnifying power
of 800, eggs may be discerned. The genus
Polytoma abounds in water where animal matter
is found. It has a double whip-shaped pro-
boscis ; as the body increases in size, it has a
wrinkled appearance, and at last self-divides into
numerous individuals. Polytoma uvella is the
only species : it is colourless and of an oblong
form. Microylena is characterized as being the
first to possess an eye — in other respects it re-
sembles the Monad : it is found amongst slimy
water-plants. A great portion of the green
matter found on stagnant water is formed by in-
dividuals of the genus Glenomorum ; they cluster

DOXOCOCCUS. 85

occasionally, and possess a single red eye, and a
double hair-like proboscis. G. tingens is oblong,
of a beautiful green colour, and the proboscis is
only half the length of its body. Dowococcm ruber
(Drop II. fig. 2) is a pretty lively little animal-
cule, having a peculiar rolling motion ; of globu-
lar form, and possessing neither tail nor eye;
the colour is a brownish-red ; D. pulvisculus is
green ; and I), inequalis , irregularly round, trans-
parent, and covered with green spots. These
interesting little creatures will be readily distin-
guished by their globular form, bright colours,
and singular motion, and add greatly to the
beauty of the animated scene, which they often
diversify. Occasionally they are found in consi-
derable numbers, and then they appear to keep

i

86 DROPS OP WATER.

up a merry dance amongst themselves, advancing
and retreating, or gliding past each other with
the most graceful movements. These are the
most interesting genera of the family Monadina.

The family Cryptomonadina is distinguished by
the individuals having a lorica , or shell, which in
some is found to be indestructible by fire. It is
either of a box or pitcher shape, and the animals
sometimes have more than one proboscis.

The first genus, Cryptomonas , has some of the
individuals green, others brown, and they may be
known from the genus Doxococcus by observing
that when the little creature is stopped in its
rotatory motion by anything in its path, it leaps
back suddenly. The individuals of the genus
Prorocentrum are only found in the sea, and help

PROROCENTRUM. 87

to form the luminous appearance which is so fre-
quently observed in the ocean. How marvellous
that these little atoms, which require a magnify-
ing power of 300, to be discerned, should produce
this extraordinary light ! The lorica of the only
species, P. micans , is pointed at the extremity,
oval in shape, and compressed. The creature
has no eye, but a proboscis, and cells can be seen
in the interior of the body. It is of a yellowish
waxy colour, similar to all the luminous Infusoria.
Lagenella euchlora has a lorica shaped like a
bottle with a neck, and is of a beautiful green
colour, but quite clear, and having a bright red
eye. It is found in fresh water, with Conferva.
Cryptoglena conica has a shield-like lorica, which
folds inwardly at the sides, two proboscides, and

88 DROPS OF WATER.

an eye, and is of a bright green colour : it moves
briskly, but springs back when obstructed. Tra-
chelomonas volvocina (Drop II. fig. 3) is distin-
guished by the lorica being spherical, and the
proboscis very long and slender ; it is green or
brown, but has a red ring on the circumference,
which is seen whichever way it turns. Another,
T. cylindrica , is of a beautiful green, with a
purple circle and red eye.

The family Volvocina contains many very
wonderful genera and species, equalled by none
among these minute creatures. They are of a
compound form, and live as it were in masses.
This is caused by their method of self-division,
which takes place, not by the body simply
dividing into two, but into many parts, and each

PANDGR1NA. 89

of these parts seeming to form a perfect individual
though joined to the rest, and all enclosed in a
transparent envelope, which expands in size as the
individuals approach maturity, and at last open-
ing sets them all at liberty. This marvellous
structure will be described under each genus, as
they differ in form and construction.

The first genus, Gyges , consists of very inactive
creatures : very slight motion of the body only has
been perceived, and they are, therefore, not so in-
teresting as many others. The lorica is trans-
parent, and the enclosed parts of a green colour.

The genus Pandorina is one of the most
beautiful for observation by the microscopist.
The transparent globular body encloses nume-
rous rather dark green animalcules, each pro-

90 DEOPS OF WATER.

vided with a proboscis about twice the length of
the body, protruding from the circumference of
the globe, and busily engaged in moving the
mass, and at the same time gaining food. The
whole has much the appearance of a mulberry,
whence the name of the English species, P. morum
(Drop II. fig. 4), which is found amongst Conferva
and Lemna. The regular rolling motion of this
beautiful creature adds greatly to the delight of
the spectator : this movement is not very rapid,
so that it can be watched with ease. I once
witnessed the disruption of the transparent case,
and the escape of the numerous individuals : some
of these had already the wrinkled appearance
| produced by the preparation for self-division. The
globe, as I watched it, seemed to have lost its

GONIUM. 91

rigidity, and each individual was busily engaged
in working its way out. I was first attracted by
seeing the mass lying without motion, except
that the green bodies within were moving rapidly,
and by degrees each made its escape after some
exertion, and swam away. It was a curious and
interesting sight.

Though not surpassing the last in beauty, the
genus Gonium is highly interesting, from its sur-
prising form and construction. It is compound,
and consists of sixteen individuals, each of a
round form, having two proboscides, and six
cords or tubes which connect it with those sur-
rounding it ; the lorica is transparent, and the
sixteen individuals are arranged in regular order,
four in the centre and three on each side, re-

92 DROPS OF WATER.

sembling “ the jewels in the breast-plate of the
Jewish high priest/’ The colour is bright green,
so that both form and colour contribute to the
beauty of the whole. The four central indivi-
duals are generally larger than their external com-
panions, and sometimes the clusters appear irre-
gular, from some of the individuals having arrived
at maturity, and become separated from the rest.
If they are all of the same size, the cluster is seen
to divide into four, each having four of the ani-
malcules, and these again form fresh clusters like
the original. I have two or three times observed
that one of the individuals, before disconnecting
itself from the rest, had divided into sixteen
distinct bodies, forming a perfect compound
mass, though the size was extremely minute.

GONIUM. 93

When swimming gently in the water, they occa-
sionally turn on the edge, when it will be clearly
seen that the individuals are arranged on a plane.
This structure is highly wonderful, and is a proof
of the extraordinary variety displayed in the works
of nature. The species I have described, G. perfo-
rate (Drop II. fig. 5), is found in clear water both
salt and fresh : it is abundant in some waters
both in spring and autumn in water procured
in October I have seen them swarm in great num-
bers, and of all sizes. It is a beautiful sight to
watch the quick movement of perhaps a dozen
specimens at once in the field of the microscope.
There are four other species differing slightly
from the above, but one, G. glaucum , has as
many as sixty-four animalcules within its lorica.

94 DROPS OF WATER.

The genus Syncryjota is distinguished by
having two loricas, one small one to each indivi-
dual, and the other common to the whole cluster,
enclosing them in its transparent folds. The long
proboscis of each protrudes from the envelope, and
gives the globe the appearance of being covered
with hairs ; neither an eye nor tail has been
perceived. There is one species only, 8. volvox :
the shape of the individuals is oval, and of a
green colour, with whitish rays in the centre,
forming a pretty berry-like cluster when united.

The beautiful creatures composing the genus
8ynura are met with in clear waters containing
Lemna, often in prodigious numbers, so that the
field of the microscope will exhibit six or eight at
once, all rolling about with the greatest ease and

SYNUUA. 95

apparent enjoyment. Now and then they stop
at a portion of decaying vegetation, and appear
to be taking a slight repast, but as the mass
forms a ball, how each individual comes equally
into contact with the food is difficult to deter-
mine; it is probable, however, that the principal
part of their sustenance is floating in the water,
and therefore they procure it even when moving.
The whole cluster seems to be moved as with one
mind, for I have watched them repeatedly, and
they move and turn as if all was under the di-
rection of one individual, and yet they are a com-
pound mass, formed of very many animalcules.
Each has an oblong yellowish body with a tail,
which is attached to the bottom of a cell in the
general envelope. Into these compartments they

96 DROPS OF WATER.

can withdraw, and can also stretch themselves
out to a considerable length when actively em-
ployed. S. uvella (Drop II. fig. 6), the only species,
has the form of a mulberry, and I have watched
the individuals when arrived at maturity separat-
ing from each other, and at last leaving nothing
but the shrivelled remains of their former habi-
tation *. it is a most interesting genus, and is
fortunately not scarce. To show what astonish-
ing powers these little creatures possess, I will
relate a circumstance I witnessed. A large clus-
ter had evidently been injured by pressure, so
that half of its members appeared to be mis-
shapen and dead. The living end was actively
employed in turning round, and for some time
I could not comprehend what this action denoted ;

UROGLENA.

97

but at last, to my surprise, I found it had twisted
itself off from the rest, and it soon swam away,
presenting the appearance of a perfect cluster.
The mutilated part left behind remained quite
still, though I watched it for some time, and I
have no doubt the members were dead.

Each animalcule of the cluster, in the genus
TJroglena , has an oblong yellow body, an eye and
a tail : by the latter it is fixed to its own par-
ticular envelope, and it radiates from the centre.
The common globe-like lorica, or mantle, covers
them all, but the proboscis projects beyond, and
gives the appearance of hairs in constant motion.
U.volvox is the only species, and is found in
turf-water.

The only species of the genus JEudorina is

K

98 DROPS OF WATER.

E. elegans (Drop II. fig. 7), and it deserves its
name, for there can scarcely be imagined a more
elegant creature. It seems to have a property
different from the other members of this family —
that of casting off the globular lorica, and forming
a new one ; probably it has not the power of ex- *
panding to suit the growth of the congregated
animalcules within it ; self-division taking place
whilst the clustered portion is retained. The in-
dividuals have no tail, but possess a sparkling red
eye, and a vibratory proboscis : the body is green,
from about fifteen to fifty of these little creatures
are assembled under the same transparent
covering, presenting a most beautiful appearance.
They are often in great numbers, but so exceed-
ingly delicate, that it is difficult to preserve

CHLAMIDOMONAS. 99

them for any time ; Pritchard says, that “ when-
ever it is attempted to retain them in large
quantities, the second day will generally exhibit
a thick mass of dead ones at the bottom of the
vessel. When a few only remain alive, if the water
be poured away, and the creatures removed into
a vessel of clear water, they will live for weeks.”
They are most abundant in the spring of the year.

A green matter is often observed on ponds
and other places, which at a first glance might be
taken for a minute weed in great quantities, but
if examined with care, it will be found en-
tirely formed of the animalcule belonging to the
genus Chlamidomonas joulviscuius , so named from
its forming a dust-like stratum on the surface.
They are often in vast quantities, and when they

100 DROPS OF WATER.

die, the bodies float, and give the surface of the
water a green coating. They are compound, like
the rest of the family, but there are never more
than eight individuals in the lorica. Each has a
beautiful red eye, which is seen even after death,

M

and a double proboscis, but no tail.

Sphcerosira volvox is the only species of the
next genus. It is distinguished by possessing a
pale green globular body, an eye, and a single
proboscis, but no tail. It divides in an irre-
gular manner, within the large transparent
globe which covers the whole ; for it is often
found, that some of the young are simple,
others already in clusters, and some oblong.
They are found generally in clear water, or
turf- water, and are often as large as those of

VOLVOX.

101

the next genus, from which they differ princi-
pally by having a single proboscis.

The Volvox is one of the most lovely of these
interesting atoms, and attains comparatively so
large a size, that its construction is easily dis-
cerned, and in the spring may be found in clear
water in great numbers, having a rolling motion,
slow and very graceful. The hollow transparent
globe contains some hundreds of single animal-
cules, attached to the inner surface, each of a
small size and green colour, having a red eye
and a double proboscis, which they protrude
through an opening in the lorica, so as to give its
surface the appearance of being covered with
moving hairs. The shell of each individual is in
the form of a bell, and it is said they have the

102 DROPS OP WATER.

power of leaving it when full grown, though they
are attached to each other by six cords, or tubes.
Besides these numerous minute creatures, the
globe often contains many globes like itself, of a
small size and green colour. Sometimes as many
as eight may be observed. The species V. glo-
bator (Drop II. fig. 8) is the most common, and
is found in the spring and summer in shallow
pools of clear water : the largest globes measure
of an inch, and the smallest about 3-b- ; Vol-
vox aureus has the enclosed globes of a golden
colour, and the individuals green * and V. stel-
latus , as the name implies, has the animalcules
of an angular shape, and the young globes con-
tained in the large one, are stellated also.

Very little is known of the organization of the

VXBRIONIA. 103

family Vihrionia , for the minute beings which
form it are very difficult to examine, on account of
their small size, many of them being invisible to
microscopes of low power. If it were not for the
circumstance of their linking together, so as to
form threads, they would escape our observation.
Sometimes two or three individuals only, form
the chain or thread, at others a greater number,
and from this circumstance it is supposed that
they are originally separate, and only join together
for mutual support, or that it is caused by the
imperfect method of self- division. One genus,
Bacterium , has a tremulous motion, but looks
like a very fine stiff thread : it requires a power
of more than 500, to see the individuals of
which it consists. The genus Vibrio is more

104 DROPS OE WATER.

flexible, and the chains move like a snake : I
have seen vast numbers in water, in which a few
leaves had been steeped. In another genus, Spi-
rillum, the threads resemble a corkscrew, and
have a brisk, lively motion ; they are found in
stagnant water. Some other genera are too
obscure to mention.

The family Astasicea has the power of changing
the form of the body at pleasure. The eye, in all
the genera, is very conspicuous, excepting in
the genus Astasia , in which the species have no
eyes. A. hcematodes (Drop II. fig. 9) contracts
and dilates itself in a curious way ; it is first
green, and afterwards becomes of a blood-red
colour. Even these little creatures have been a
cause of terror to the superstitious, for they in-

EUGLENA. 105

crease at an astonishing rate, and, assuming a
blood-red colour, give a tinge to waters, for
which the ignorant cannot account. It has a
spindle-shaped body. A.pusilla occurs in my-
riads, so as to form occasionally quite a stratum
on the surface of the water : it has no colour.
A. nivalis is found in snow in Switzerland.

Most of the species of the genus Euglena are
beautiful objects, the bright colours rendering
them very attractive. JE. sanguinea (Drop II.
fig. 10) is of a spindle shape, the head rounded,
tail short, proboscis long : the colour varies —
some may be found quite green, which seem to
be the young ones, others mixed red and green,
and others quite red. E. viridis is green,
except the head and tail — these are white,

106 DROPS OP WATER.

and the eye is red. I have seen this species in
such numbers, that there appeared a perfect
swarm, though the water was obtained as late in
the year as October, their elegant form and
bright colours rendering it a beautiful sight. E.
pyrum is dark green, pear-shaped, and swims
rather swiftly. E . pleuronedes is like a small
green leaf with a short stalk : it is flat. E. Ion -
gicauda has the power of twisting its body into
a spiral form, and is also somewhat leaf-shaped.
This is an elegant animalcule, the form very
curious, and the colour sparkling green ; the tail
is as long as the body, and, though colourless,
is very conspicuous. When two or three are
moving gently near each other, they form a very
pretty scene. E. acus has a slender body, with

»

COLACTUM. 107

a pointed tail ; the head and tail have no colour,
but the body is bright green, and the eye bril-
liant red ; it is a beautiful species, not only from
its bright colours, but from the elegance of its
form, and its mode of swimming; when sta-
tionary, it frequently changes its shape. There
are several other species, but those mentioned
are the most common : I have found them all in
pond-water.

A little creature, attaching itself to other
bodies by a foot-stalk, and frequently found on
Rotatoria and the crustaceous creatures allied
to the water-flea, is called Colacium. I have
seen it covering the stalks of the Vorticella con -
vallaria , so as to give the whole the appearance of
a minute branch of green leaves. The species
• — %

108 DEOPS OP WATEE.

C. vesiculosum has a very short foot-stalk, the
body bright green, and of an oval form ; currents
are seen near the fore part of the body, when
coloured particles are introduced into the water,
so that there is, probably, a vibratory proboscis.
C. stentorinum is more cylindrical in form.

The genus Distigma is formed of individuals
which neither swim nor produce currents, but
they creep at the bottom of water, and change
their form in a curious manner : they appear
to have delicate black eyes. D. tenax is the
largest, and it contracts and dilates very visibly ;
the colour is yellowish. D. viride has green
granules within. Both are found amongst Lemna
and Conferva.

The family Dinobryonia differs from the last in

DXNOBUYON. 109

having a lorica, which has the form of a little
pitcher ; the body still retains the power of chang-
ing its shape at will. One genus, Dinobryon , pos-
sesses more beauty than many others among these
interesting creatures. D. sertularia (Drop II.
fig. 11) is more like the flowering spike of some
grasses than anything else to which I can compare
it, except, perhaps, a branch of coral : the little
creature resembles the Euglena , mentioned before,
but is of a pale yellow, and has the power of
stretching itself out, and also assuming a globular
form within its lorica. It has a red eye, and a
long proboscis which assists not only in propel-
ling itself through the water, but also the others
to which it is attached. Each individual lorica
seems to have sprouted from the one below, till

L

no DROPS OF WATER.

at last there is formed quite a little spike, or
shrub, of these delicate loricas, and the elegant
inhabitant. It is so extremely transparent that
it requires very nice adjustment of both in-
strument and light, to see it well ; — it is
lost sight of by the smallest alteration of the
focus, but, when fully seen, is an exquisite
object. It is not attached, but moves slowly in
the water, turning gently round. I have occa-
sionally met with bog-water abounding in this
delicate creature : the groups differ in size, some
having only two or three collected together,
others formed of a dozen, and then nothing
can exceed the beauty of this compound mass.
It is found principally in the spring.

The family Amcebcea consists of one genus,

AMCEBA. Ill

Amoeba. This singular animalcule has neither
foot, eye, nor proboscis ; it appears like a trans-
parent bladder, and has the power of putting
out at all parts of the body processes which
help it to creep slowly — these it contracts and
dilates continually, so that it is constantly chang-
ing its form ; this renders all the species very
interesting objects for the microscope. A. prin-
cess (Drop II. fig. 1 2) is of a pale yellow colour,
and its manner of progression is very amusing to
watch. It puts out a portion of its body which
appears quite transparent for an instant, and
then the granules with which the body is full,
run forward into it and fill it ; at the same time
other portions undergo the same extension, and
thus it moves slowly along. The protruded parts

112 DROPS OF WATER.

of tlie body do not seem to be always the same,
but to arise from any part at the will of this sin-
gular creature. A. verrucosa is smaller, and with
shorter and more blunt processes. A. diffluens
has no colour, and A . radiosa expands its pro-
cesses in the form of a star, though when at rest
it looks like a lump of jelly.

The family Arcellina differs from the last in
having a lorica of a pitcher- or dish-shape, and
moves by the soft processes protruded beyond it.
The first genus is Difflugia, which has the pro-
cesses cleft into several parts, and the body
enclosed in an opake lorica. D. proteiformis
(Drop II. fig. 13) is of a globular or oval form, the
lorica encrusted with minute grains of sand : the
transparent processes are often as many as ten in

ARCELLA.

113

number ; it is found amongst Conferva, as well as
the next genus, Arcella , which differs in form,
being flatter, and the surface not covered with
sand. A. aculeata has spines upon its surface, and
a large opening. A. vulgaris has the lorica round,
and covered with rows of minute granules, and
A. de7itata is of a hemispherical form, and has
the margin dentated. The last genus of this
family, Cyphidimn , has only one dilated process ;
the lorica is pitcher-shaped, with protuberances
upon it, which give it a square form : the pro-
cess by which it moves may be termed a foot,
and resembles the body of the genus Amoeba.
Cyphidium aureolum is the only species.

DROP III.

The objects contained in tbe drop under con-
sideration are of a different character to those
in the last. Many of them have very lively
movements, others are attached, but at the
same time full of life and motion. One family,
the Vorticellina, will be found highly interesting,
and, most of them being fixed to weeds, they
are more easily examined than many others.
Two small and insignificant families are ar-
ranged before it in the classification. The family

1. Stentor Hoeselii .

- 5 .

Co,“#3mi,ii‘ia. rrr.berbis .

2. Vortleelia ccnve.: ; aria. .

■;'4;

\tf.T a chilo cexca ol o r .

3. C ar die s ram. ' .

7

Silr s m a4ar uilc; a t eli.e. .

4. Vagimcola '.rystalirtia. .

.PaTainsciair. a/ar-eis a

9 . aSujlotes ekaraa

i lies del

Reeve &.Nuhols . z 'nip •

CYCLIMUM. 115

Cyclidina contains animalcules having no lorica
and no eyes ; bristles, or cilia, are the organs
used in locomotion. The genus Cyclidium has a
compressed body, and the cilia are placed in a
single circular row. C. glaucoma is abundant
in the spring, and may be known by its oblong
body, the ring of cilia, and its peculiar move-
ment, which is generally quick ; but frequently
the little creature stops, and then springs sud-
denly to another spot, with a light, graceful mo-
tion. The family Peridincea possesses a lorica,
and probably eyes, and the cilia are in the form
of a crown. Some of the genera have a deli-
cate proboscis, in addition to the cilia ; they are,
however, insignificant in size, and I shall pass
them over, to give more space to the next family.

116 DROPS OE WATER.

The individuals of the family Vorticellina form
one of the most interesting groups. Some are
free, others are attached either singly or many
together, forming little tree-like masses, where
each individual may be likened to a leaf : this is
caused by their imperfect self- division. They
have no lorica, but numerous cilia arranged in va-
rious ways — in some genera they cover the body
! all over, and in others they merely surround the
mouth, or form a wreath. Eyes have not been
observed, but they have some quick mode of
knowing when danger approaches, and shun it
very rapidly. The mode of increase is by self-
division, either by the body completely dividing
into two separate individuals, and becoming per-
fectly independent of each other, or by the body

STENTOR.

117

dividing, but the two remaining attached by a
stalk ; they also increase by buds issuing from
the sides of the parent body.

The first genus of this wonderful family is
called Stentor ; the animalcules are free, in the
form of a trumpet, and of considerable size, as
they may be seen without a microscope, floating
as specks in the water. I have found the black
species so numerous in some waters as to give
the appearance of a black powder having been
spilled on the surface. All the species are active,
lively creatures, and extremely amusing to watch.
They adhere, when feeding, by the pointed ex-
tremity of the body to a leaf or stalk, and stretch
themselves into the form of a trumpet, expand-
ing at the larger end where the mouth lies, and

118 DROPS OP WATER.

where a wreath of large cilia are in constant vi-
bration, enabling them to draw within the body
the food they require : this consists of Monads,
and various little creatures ; and as most of thS
species are transparent, the digestive cells may be
plainly seen filling gradually with these unfortu-
nate little beings. Stentors increase by self-divi-
sion longitudinally, and also by eggs. S. Mill -
leri is white, transparent, and large. JS. Roeselii
(Drop III. fig. 1) is equal in size, but rather
more yellow in colour. They both contract, when
swimming, into the form of an oblong ball, but
when fixed, stretch out considerably ; when two
or three are attached near each other, and
all have their mouth-cilia at work, the current
they form in the water is quite extraordinary,

TRICHODINA. 119

and very interesting : small cilia cover the whole
of the body. S. polymorphus has green masses
within, supposed to be eggs. S. igneus is yellow,
or rather red, and is smaller than the rest. S.
niger is very dark in colour, and does not stretch
out to so complete a trumpet-shape as the rest :
it swims rapidly, and is very abundant in the
spring, making the surface of the water quite
black in patches. S. caruleus has the ova blue,
which may be seen through its transparent body.

The genus Trichodina has no cilia on the sur-
face, but a wreath of them at one end of the
conical body. Uirocentrum has no cilia except
a wreath. U. turbo has a transparent, three-
sided body, and a short tail : it is found
amongst Lemna and other weeds.

120 DROPS OP WATER.

The genus Vorticella is one of the most in-
teresting amongst the Infusoria.’ The species
V. convallaria (Drop III. fig. 2) is the most
common, has a bell-shaped body, is perfectly
transparent, and attached by a flexible stalk of
considerable length to weeds, &c., so that it can
be watched with great ease ; and a more amusing
sight cannot be met with, than a number of
these beautiful beings grouped together, all
busily engaged in procuring food by the aid of
their cilia, which they keep in constant motion,
thus producing a strong current in the water,
and drawing into their mouths small atoms upon
which they feed. When any object alarms them,
they immediately contract the strong muscle,
which, with a power of 250 diameters, may be

VORTICELLA. 121

seen within the stalk : this motion carries the
body instantaneously to a considerable distance ;
after a short time it uncoils again, and the ani-
malcule renews its occupation. This stalk, which
is about five times longer than its body, is a
marvellous structure : — the muscle within, at the
will of the animal, can contract into many coils, so
suddenly that the eye cannot follow the motion,
though the effect is seen by the removal of the
body to a distance ; — the uncoiling is not so
sudden, and much more graceful. Vorticellce
group themselves together in hundreds, when
the scene is very animated, first one and then
another contracting ; and often the whole party
recede at once, as if animated by the same will,
then they expand again, and the same scene is

M

122 DROPS OF WATER.

displayed; the current in the water, formed
by the group, causing numerous little ani-
malcules and vegetable productions to whirl
about in a curious way. This current may be
observed more clearly still, if a small portion of
carmine or indigo be placed in the water, at
the same time the animalcules will be found to
eat it in vast quantities, the stomach cells be-
coming coloured either red or blue. They in-
crease rapidly by three different methods.
Though the act of depositing eggs has not
been perceived, still young ones appear in vast
numbers attached near the old ones to the same
substance, and gradually increasing in size. A
full-grown one will frequently be seen to have
a double appearance, and if this is watched, a

VORTICELLA. 123

fissure will soon be perceived — two bells will be
formed, and in time one will twist itself off, and,
swimming freely about for a period, at last fix
itself, and form a stalk. One extraordinary cir-
cumstance has been witnessed by those who
have watched minutely — that the lower portion
of what may be called the new being, and which
was attached to the stalk, now becomes the
mouth, and is surrounded with cilia, whilst the
upper part closes and produces the stalk. I
have frequently observed a circle of cilia in ac-
tive motion on the lower part of the newly-
formed bell, even before it had left its parent,
but have never been so fortunate as to observe
what follows. When this newly-formed creature is
swimming about, it might be, and has been, taken

124 DROPS OF WATER.

for a new genus. Besides this extraordinary
method of increase, buds have been perceived on
the sides of the bells, which gradually increase
in size, and form new individuals. By these
various means their numbers augment astonish-
ingly, and this increase may be watched, if a
stalk of duckweed or other substance to which
a few are attached, be put by itself in a small
vessel of water, and examined by the microscope
every day. I have often selected a small group,
and keeping it in a vessel alone, have observed
them increase to several hundreds in the course
of a short time. They fall from their stalks and
die, if deprived of air, for I have more than
once kept a number under a glass cover, for
twenty-four hours, and found half lying dead in

CARCHE8IUM. 125

heaps at the bottom, and in double that time all
had perished. This species is found principally

on duckweed. V. campanula is larger than

6.

V convallaria , and rather brown in colour :
it has a bell-shaped body, but truncated in
front. The single animalcules may be discerned
without a glass ; and a mass of them appears like
a bluish matter attached to water-plants. There
are several other species, all differing slightly
from those mentioned, but having the same gene-
ral appearance and habits.

The next genus is Carcfiesium, and it differs
from the last in its imperfect mode of self-
division. There is one main stalk, which has
the power of being contracted in coils, like that
of the last genus ; but it is branched, and each

126 DROPS OF WATER.

division bears a bell. C. polypinum (Drop III.
fig. 3) has a bell-shaped body of a white colour,
and in size is equal to the Vorticelia convallaria.
These groups are particularly beautiful, and the
actions very amusing to watch. Each individual
bell has the power of contracting slightly, and
drawing in its cilia, but the long stalk is only
common to the whole number ; how they
agree to contract that, it is difficult to say, and
yet they are constantly repeating this movement,
and again stretching themselves out in the most
elegant manner.

The genus Epistyles has a stiff, inflexible,
hollow stalk, which is generally branched,
like the last genus. E. plicatilis has a forked
stem, the bell- shaped body has rather a yellow

EPISTYLIS. 127

cast, and, when contracted, has a folded ap-
pearance. E. anastatica has an oval-shaped
body, and does not form folds when contracted :
it is often found on the shells of small mollusca.
E. digitalis is small, but much branched, and is
often abundant on the body of the Cyclops qua -
dricornis , where it appears to be indifferent to
the rapid movement of that active creature,
whose passage through the water one would
suppose must destroy the life of so delicate a
being. E. grandis has not an erect stalk, but it
is often of great length, even as much as several
feet : it looks like blue slime to the naked eye.
E. nutans has the body drooping when the cilia
contract, though it is upright when they are
expanded. It is curious to see this little crea-

128 DROPS OP WATER.

ture suddenly fall into a drooping posture when
danger approaches, as if its minute stalk had a
joint near where it is attached to the main stem ;
after the lapse of a moment, it again rises, and
renews its search for food. E. parasitica is small
and solitary. There are several other species.

The species of the genus Opercularia have a
stiff stalk, and much branched ; but the bells,
or little bodies, are of different shapes and sizes.
The genus Zoothamnium has a flexible stalk, and
the bodies of different forms. Z. arbuscula is much
divided, forming objects like beautiful little trees,
or plumes of feathers. Most of these curious
genera of the family Vorticellina may be seen with
ease by the aid of a good microscope, and will
amply reward tne patient investigator by the

OPHRYDINA. 129

pleasure derivable from watching the habits and
peculiarities of these extraordinary and beautiful
little beings.

In the next family, Ophrydina , I shall only
mention two genera — Vaginicola and Cothurnia.
Vaginicola crystallina (Drop III. fig. 4) has a
transparent, crystalline, pitcher-shaped lorica,
fixed to the stalks of duckweed ; the body is
bright green, from the granules with which it
is filled, and often appears double: it expands
slowly as if afraid, and protruding from its lorica,
it then unfolds its cilia for a short time, but
again suddenly retires. V. decumbens has the
| lorica flat on the stalk or leaf — not erect, like
the last. Cothurnia imberbis (Drop III. fig. 5)

I has the transparent lorica round at the bottom,

130 DROPS OF WATER.

and supported by a short stiff stalk : the body
is yellow; — often attached in numbers to the
Cyclops quadricornis.

We now come to a part of the classification
where the families and genera are exceedingly
difficult to describe ; I shall only, therefore,
mention a few of the most striking, leaving the
student to refer to works of greater science when
the excited curiosity is anxious to be satisfied.
The little creatures are of higher organization
than those described before, and many of them
much larger. They are all more or less bladder-
shaped, the body generally covered with delicate
cilia, some possessing loricas, and others none;
some, bristle-like appendages, and a few having
long necks ; they either swim about or creep on

TRACHELOCERCA. 131

plants. One genus is named the swan-neck
animalcule, from the extreme length of that
part in some of the species ; indeed, they may
he called all neck, for the body is small com-
paratively, and they are more frequently seen
with the neck alone projecting from the edge of
a leaf. Trachelocerca olor (Drop III. fig. 6) has
a spindle-shaped body, with a very long flexible
neck, dilated at the end, where the mouth is
situated. The animal creeps at the bottom of
the water, or on the leaves, and is constantly
moving its graceful neck in all directions amongst
the weeds : when two or three are feeding close
together, it is curious to watch the actions of
this flexible member.

Another singular creature, somewhat similar

132 DROPS OF WATER.

in form to the last, though differing in many es-
sential particulars, is the Traclielius anas : it has
what at first sight might be taken for a neck,
but the mouth not being placed at the end, it
cannot be so considered. The mouth is at the
base of this long appendage, and may be seen
occasionally whilst the long process is waving
about ; this, and the cilia on the body, are the
organs by which it moves.

Bursaria truncatella (Drop III. fig. 7) is
another marvellous being, large, and easily dis-
cernible by the naked eye ; found in water
where there are decayed beech-leaves. It is
oval in form, truncated in front, and having a
simple row of cilia there, but the body is entirely
covered with small ones disposed in rows. It

BURSARIA.

i.

133

glides about in a quiet manner, between the
portions of vegetable matter, and appears to
have the power of compressing its body to suit
the size of the passage. The internal cells are
very transparent, and I have seen Rotifers and
other small animalcules lying within, as if only
just swallowed. Having procured some water
which contained a large number of these crea-
tures, I had an opportunity of making observa-
tions about their death, which I do not see men-
tioned by naturalists : — whilst watching a very
fine one, I perceived that a part of its body
seemed to be separating from it, particularly
the contents of the internal cells ; this continued
for some time, until at last the whole body had
dispersed, and was lying on the surface of the

N

134 DROPS OF WATER.

water in minute portions; but the most mar-
vellous part of the proceeding was, that the cilia
continued to vibrate the whole time, not only
as long as the body was partially hanging to-
gether, but each little portion, as it floated away
from the larger mass of the body, had consider-
able motion in it from the action of the cilia, and
this continued for full five minutes, or perhaps
more, after each portion had separated from
the main body. The animalcule itself remained
turning slowly round during the process ;
and the motion only ceased when all was dis-
persed. I witnessed this curious fact many times
before I discovered what may be considered
the reason of this extraordinary dispersion : I
believe it to have been caused by the evaporation

BURS ARIA. 135

of the water, as its death always seemed to take
place after the drop had been under the micro-
scope a certain time, and though there was still
sufficient water remaining for the body to move
within it, with some freedom, there might not
be enough for its comfort and life. I caused
the death of many specimens, before this idea
occurred to me, and I have not met with any-
thing similar to it, except once, in the case of a
Stentor , which I saw disperse in the same extra-
ordinary way. That the bodies of these little
creatures should be dissipated in the water after
death is not surprising, but that they should
commence breaking up during life, — at least,
that the cilia should retain so much muscular
power when separated from the body, — is won-

136 DROPS OF WATER.

derful. The more we watch these little creatures,
the more we find to admire and interest us.

I must mention the Paramecium aurelia (Drop
III. fig. 8), because it is found sometimes so very
abundant in stagnant water. I have seen it in
such numbers in one drop, that the little creatures
were almost close together, and yet all gliding
about in seeming enjoyment : they were in
water in which I had steeped a few leaves for

some weeks. They have an oval cylindrical

| body, and have short cilia placed in long lines,

! those near the mouth rather longer. The di-

gestive cells are very numerous ; and it is stated
that these little creatures have the sense of taste,
for if a mixture of carmine and indigo be put into

! the water, some will take only one substance, |

r

1 , : j

EUPLOTES. 137

and some the other — and this can be seen by the
colour in the stomach-cells.

The last genus I shall mention in the class
Polygastrica is PJujolotes , a genus with which ob-
servers soon become familiar, not only from the
beauty of the species, but from the peculiar move-
ment of these little creatures. They are of an
oval form, very transparent, and brightly coloured
with spots of green and red ; they have cilia,
and are furnished also with what are called
setse, and styles; these are hair-like appendages
variously situated, which, by their quick mo-
tions, enable the animalcule to move most rapidly
through the water ; they also dart back sud-
denly, and, turning round, again advance to the
place where they were gaining food : this back-

138

DROPS OF WATER.

ward and forward motion is frequently repeated,
and occasions them to be easily recognized.
They make a powerful current with the cilia
near the mouth. Euplotes char on (Drop III.
fig. 9) is, I think, 'the most common, and is
found in infusions. U. patella is larger, more
round in form, and abounds most where duck-
weed is growing. There are several species of
this interesting genus found in sea-water.

DROP IV.

The animalcules comprised under the class Ro-
tatoria are of a higher organization than those
already mentioned ; the body is of a more
definite form (not changing its shape, or dividing
spontaneously, as is the case with many of the
Polygastrica :), having but one digestive cell, in the
form of a tubular alimentary canal, being pro-
vided with a rotatory organ, and in general a
single foot, or process, by which it clings to sub-
stances in the water. Of the cilia, and their

140 DROPS OF WATER.

wonderful construction, I have spoken in the in-
troductory chapter ; — by their means a whirlpool
is caused in the water, smaller creatures are
drawn into it, and swallowed by the mouth ; this
apparatus forms, also, their means of locomotion,
and in many genera the swimming is very rapid.
These delicate cilia can be withdrawn at pleasure,
and covered securely by the rest of the body.
The gullet contains a set of sharp teeth, which
grind down the food very rapidly, and which may
be seen constantly in action whilst the animalcule
is feeding. The foot — or tail, as it is sometimes
termed — is in many genera of very wonderful con-
struction ; it is formed so as to enable the little
creature to make it long or short at pleasure, by
one part sliding within another, on the same con-

ROTATORIA. 141

struction as tlie tube of a telescope. It is very
interesting to watch this exquisite mechanism,
and to observe how wonderfully all the parts are
adapted to each other. The Actinurus Nejolunius
shows this formation in the greatest perfection.
Other genera have a disc at the extremity, like
the leech, by which they hold very tightly ; and
many have one or more toe-like divisions.

The Rotatoria are reproduced by eggs, either
hatched within the parent body before exclusion,
or fixed to weeds and other objects floating in
the water. Some few genera attach the eggs to
their bodies, and carry them about for some time,
appearing not to be in the least inconvenienced.
The number of eyes varies in the different genera :
they are generally red. As the Rotatoria are

142 DROPS OF WATER.

large, comparatively speaking, a glass magnifying
250 diameters is quite sufficient to see them with
perfect ease. I shall only describe a few of the
most common genera, referring the student to
Ehrenberg’s or Pritchard’s excellent works,
where each species is minutely described, and
as ably illustrated as means will allow.

One of the first genera of the Hotatoria ,
though it will not be the first to attract the atten-
tion, is a creature somewhat resembling a long
narrow fish with a forked tail. The Iclrthydium
podura has a transparent, colourless body, long,
and constricted so as to form a head ; it swims
rapidly, but is generally seen creeping : the tail is
formed of two parts, like a pair of pincers.

The next genus, Chcetonotus , is more common,

FLOSCULARIA. 143

and peculiar, having its body clothed with
hairs, the form also resembling in some degree
that of a caterpillar : it is generally seen creep-
ing on the stalks of duckweed, and occasionally
swimming with considerable ease. C. larus is the
most plentiful species, and particularly abundant
in muddy water.

The genus Floscularia , though consisting of
species always attached to water-plants, and there-
fore less lively than most of the Rotatoria , is very
beautiful, and highly interesting. The indivi-
duals each dwell in a transparent case, which is
affixed to plants, and the body is attached by a
slender foot to the base, having the power of ex-
panding or contracting itself at pleasure. When
contracted, it is shorter than the cell, but, if

144

DROPS OF WATER.

watched, will be found gradually to expand, and
to stretch itself far beyond the edge of the case,
and then to unfold its curious, rotatory organ,
which is divided into six lobes, each provided
with many cilia. A current is then observed in
the water, though the cilia are not seen to move ;
small objects are drawn into the mouth very
rapidly, and swallowed, to be ground down by
the chewing apparatus* which may be observed
constantly at work. When danger approaches,
the creature contracts suddenly, and is safe
within the case in an instant ; this protective
case is so exceedingly transparent, that even the
brightest light will fail to render it visible, unless
it is partially covered with loose matter which
has been drifted to it by the water ; or it may

FLOSCULARIA.

145 i

I

!

be seen, when this is not the case, by colouring
the water with carmine. The presence of eggs,
also, near the body of the parent, shows that there
is a case, though it may not be visible to the
eye. F. ornata (Drop IV. fig. 1) is the most com-
mon species : it has longer cilia than F.probosci-
dea , but no proboscis. The mode of increase is by
eggs, which are deposited within the case, and are
of considerable size, and of an oval form : I have
seen four or five within the transparent covering
of the old one, and once witnessed the young
animalcule hatching. The two red eyes are very
distinctly visible when the little creature is nearly
ready to burst the shell ; and on one occasion,
observing that these eyes were more conspicuous
than I had previously seen them, I watched very

o

146 DROPS OP WATER.

attentively, and at last had the pleasure of seeing
the young one escape first into the case of the
parent, and from thence into the water, where,
though so small, it was conspicuous from the
bright red eyes ; but it swam so rapidly, that I
could with difficulty follow it ; and at last it was
lost among the surrounding weeds, which seemed
to form a wide world for the little creature. After
a short life of freedom it attaches itself like its
parent, and forms a case. In some waters these
interesting and beautiful creatures abound.
I have counted between thirty and forty speci-
mens on one stalk of duckweed, in all stages of
growth : — those of middle age are bright and
clear, the case nearly invisible and containing
no eggs, the body slim, and very elegant in

STEPHANOCEROS. 147

form ; the old ones have the case large, covered
with extraneous matter, and with as many
as five eggs clearly seen within it, — the body
larger, of a more plump form, much coloured,
and capable of stretching out, when feeding, to a
very considerable length.

There are other genera of attached Rotatoria ,
which I will slightly describe, but that above
mentioned is the one most generally seen. Ste-
jphanoceros EicMornii is a very wonderful crea-
ture, and of considerable size, but unfortunately
very rare. The case is so transparent, that it
is rarely seen unless the water is coloured with
paint : it is larger than that of the Floscularia
ornata, and Dr. Mantell describes it as “ attached
like a collar round the body at the upper margin,

148 DROPS OF WATER.

near the base of the rotators; so that its
border becomes inflected when the animal shrinks
down towards the bottom of the case.” The ro-
tators here spoken of are five deep lobes of the
rotatory organ, each having fifteen circular rows
of cilia one above the other, up to the points ;
these lobes, or arms, . the animal spreads out
when it emerges from its case, and occasionally
uses them as a “ prehensile instrument.” They
are extremely beautiful and curious, and in a con-
stant state of activity, frequently shrinking into
the case, and again emerging and displaying the
beautiful form of the lobes. Dr. Mantell once
saw one he was watching, capture a Stentor by
the aid of these arms, but he does not say
whether it was eaten. They seem principally to

LIMN IAS. 149

feed on Monads, and other small creatures. The
eggs are retained within the case till they are
hatched. The Stejohanoceros has one eye, which
is very conspicuous in the young state.

The Limnias has only two lobes to its rota-
tory organ, and the case, though at first white,
becomes of a brown colour, and is often covered
with other substances which adhere to it. The
rotatory organ of the Limnias ceratophyTli
(Drop IY. fig. 2) has a singular appearance when
the creature is feeding ; — the cilia surrounding the
lobes are very short, and, when vibrating very
rapidly, have the appearance of a moving band of
light round the edge, which is very deceptive to the
eye, and the mind can scarcely conceive that the
effect is produced by so simple a cause as small

o 3

150 DROPS OF WATER.

vibratory cilia ; below this apparatus are seen the
grinding jaws in motion. The animal frequently
bends its body, first to one side, and then to the
other, as if it were looking over its dark case for
prey ; and at that time are seen several processes,
which form part of the body. The Melicerta,
another genus of stationary Rotatoria , has four
lobes : the case has a granulated appearance,
and is of a brownish-red colour.

Of the free genera of this class, a few species,
more highly interesting and more common than
the rest, can be alone described.

Microcodon c/$ms(Drop IV. fig. 3) is a beautiful
little animalcule, being in shape like a bell, with
a long undivided foot, which it has the power
of bending at right angles to its body ; the rota-

NOTOMMATA. 151

tory organs are shaped like the figure eight, and
have bundles of bristles projecting beyond ; it
seems to have a small red eye. It is a lively
little creature, and extremely difficult to observe
with accuracy.

Notommata longiseta (Drop IV. fig 4) is of a
very curious construction and appearance, and
easily known by its long double tail, which is
often more than three times the length of its body ;
the two portions are needle-shaped, one longer
than the other, and slightly curved : the body is
small and cylindrical, the rotatory organs nu-
merous, and not conspicuous. It is an active
creature, and has the power of leaping, or at least
changing its position suddenly, for I never ob-
served that this action gave it much onward

152 DROPS OF WATER.

movement; it seems more frequently to turn
round only, and is probably assisted in this
action by the long stiff forked tail, or foot. It
appears to feed on other species of Rotatoria , as
well as the smaller Polygastrica .

Synchceta pectinata (Drop IV. fig. 5) is a
beautiful animalcule, but very difficult to watch,
from its quick motions, and the transparency of
its body. It occasionally, however, fixes its
short forked tail, and then twirls round rapidly
for some time, vibrating its numerous rotatory
organs, and drawing towards it many objects
in the water. Between the clusters of ciliated
organs, are strong bristles, which are easily seen
when the creature is thus comparatively quiet.
The body is short, tapering towards the short

SCABIDIUM. 153

pointed tail, but very broad at tbe head, which
has two shoulder-like appendages, giving it a
peculiar look, and rendering it, with other circum-
stances, easily distinguished. It has a large red
eye. Altogether, this is an interesting specimen,
but from its liveliness rather tantalizing, for it
may be followed for a considerable time before it
remains sufficiently tranquil for any of its pecu-
liarities to be noted. Another species, found
in the Baltic, produces a phosphorescent light,
observed by Dr. Michaelis.

Scandium longicaudum has a long foot, twice
the length of the body, and seemingly jointed
in the middle. It is divided at the extremity
into two toes : with the aid of this curious ap-
pendage, the animalcule has the power of leaping

154 DROPS OF WATER.

or springing very quickly, not to a great dis-
tance, but changing its place, and half turning
round at the same time. It has one eye, and a
compound rotatory organ, armed with a hooked
bristle ; the body is oblong. This is an interest-
ing object, and found in the summer, though
not very commonly.

Another leaping animalcule, the Folyarthra
trigla (Drop IV. fig. 6), is of very singular con-
struction. The body is almost square, and on
each side are six strong narrow fins, or bristles,
which enable it to swim quickly, or leap sud-
denly. It carries its eggs attached to the outside
of the body. The small polygastric animalcule,
the Colacium , mentioned at page 107, is often
found infesting both its body and fins, and yet

LEPADELLA. 155

its progress through the water does not seem
to be impeded.

j Uattulus lunaris (Drop IV. fig. 7) is one of
the smallest of the Rotatoria , but often seen in
turfy pools, and soon distinguished by its dimi-
nutive size and curved body ; the foot is short,
and curved also.

The genera mentioned from Notommata to
Rattulus have no lorica.

The individuals of the next family are clothed
with a lorica ; some of the genera are common,
and interesting. lepadella ovalis (Drop IV.
fig. 8) is often seen in immense numbers in
stagnant water, and is a pretty and lively
animalcule, though said not to possess eyes ; it
guides itself, however, with unerring precision,

156 DROPS OF WATER.

and, if deficient in sight, has other senses of
equal value. The lorica is flattened, and of an
oval form ; the small foot divided at the end,
and moving about in every direction. It ap-
pears to fix the foot on some substance in the
water, and then to move the body rapidly on
every side, as if in search of prey; the small
rotatory organs are in constant motion.

Mastigocerca carinata (Drop IY. fig. 9) is one
of the most elegant of these interesting crea-
tures : its oval body, with a crest on the back,
seems to take a variety of shapes as it spins
round in the water ; its long needle-like tail is
straight when swimming in one direction, at
others bent at right angles to the body whilst it is
stopping to examine food. It does not swim so

EUCHLANIS. 157

rapidly as many others, and thus is more easily
examined : its rotatory organ is small, and divided
into four parts ; it has one eye, and the body is
so transparent that the internal parts are easily
seen, giving colour and seeming solidity to this
otherwise fragile-looking creature. The crested
and raised part of the lorica on the back, is very
curious, but the use of it is doubtful; other
genera have a lorica of similar construction.

JEuchlanis triquetra is of large size and sin-
gular form, but is unfortunately rare, and only
found in turf-water. The lorica is very trans-
parent, and three-sided, the crest on the back,
and the rather sharp flattened sides, forming,
when seen endways, a perfect triangle ; the tail
is divided into two sharp points, and proceeds

p

158 DROPS OF WATER.

from the under side of the lorica, not from the
end of the body. The rotatory organs are divided
into several bundles.

Salpina mucronata (Drop IY. fig. 10) is com-
mon, but not less interesting on that account.
It is smaller than the last, but of sufficiently
large size to render it easy to watch its move-
ments. It is lively, but often attaches itself by
its forked tail to weeds, for some time, when
busy in procuring food ; indeed, it is, I think,
particularly voracious, for I have watched a spe-
cimen seemingly thus employed, for two hours
at a time. In my opinion, this animalcule feeds
on vegetable substances almost entirely, for I
have frequently seen it clearing away the green
pulp from the stalks of duckweed, and leaving

SALPINA. 159

transparent spots, which before were opake. The
three-sided rather rough lorica is of very curious
form ; the under side is flatly rounded, the back
crested, the sides also project, and the space
between is hollowed out ; at the end, where the
head is placed, it has four points, or horns, and
at the base only three, where the two-forked tail
projects. It has a compound rotatory organ,
which it withdraws completely into the lorica
when alarmed. The red eye and toothed jaws
are easily discerned, the latter moving very ra-
pidly when the creature is feeding. The eggs
are large, frequently found attached to weeds, and
so transparent that the young are visible within ;
these, when nearly arrived at maturity, produce a
vibratory motion, easily seen. This animalcule

160

DROPS OP WATER.

-

is found principally among duckweed, and is
pretty numerous in spring and summer.

Metopidia lepadella greatly resembles the
genus Lepadella mentioned before, being flat,
oval, and having a forked foot, but it has two
red eyes. It is very transparent, particularly
the sides ; is lively, and not uncommon.

The Stephanops lamellaris is a very pretty
creature, and is easily known by its head having
a kind of hood extended over it, which is trans-
parent, and cannot be withdrawn within the
lorica, but probably serves as a defence to the
delicate cilia. Its swift movement renders it
difficult to observe ; and before I had seen the
little creature actually withdraw its cilia, I
imagined the hood was an appearance only.

J

CALLIDINA. 161

caused by the rapid movement of the cilia and
the swift motion through the water, but repeated
observation undeceived me.

The individuals of the family next under con-
sideration are not cased in a lorica, and are very
peculiar, from the form being more or less spin-
dle-shaped, and from their having the power of
sliding some portions of the body within each
other, like the tubes of a telescope, so that it is
either long or short at the will of the creature.
This construction is very wonderful, when we
consider the mechanism and muscular power
required to effect it. Adinurus Neptunius is the
most striking example of this peculiarity. The
genera are as follows : —

The Cattidina elegans is found in bog-water,

p 3

162 DROPS OF WATER.

and in water in which oak-leaves or bark has
been steeped. It is of an elegant spindle-form
when stretched out, the rotatory organs small,
the foot forked, and having also processes above ;
the body is very transparent, and the jaws can
be distinctly seen engaged in grinding down the
food. At first sight it greatly resembles the fol-
lowing genus, but the rotatory organs and want
of eyes distinguish it.

Rotifer vulgaris (Drop IV. fig. 11). — This in-
teresting animalcule was one of the earliest, dis-
covered by the aid of the microscope. It was
first described by Leeuwenhoek about 150 years
ago, and has never since ceased to be a favourite
with those possessing microscopes. It is easily
obtained in spring and summer, being abundant

ROTIFER. 163

in most waters where decaying vegetables are
found ; or a store of them may be kept in a jar
by following a plan which has been mentioned
to me by one interested in the subject. “ Pill
a three- or four-gallon jug with rain-water (not
butt- water), which will serve for a year or two to
keep a half-pint mug at the same level (with
water from the jug). Into the mug put a few
sage-leaves tied together, and when they are not
to be obtained, in winter, a little bundle of hay
about the size of the joint of a finger will answer
as well. When the sage -leaves decay and sink,
put in a fresh supply ; the Rotifer vulgaris will
always be found at the surface near the sage-
leaves ; and when dirt forms at the sides of the
mug, if a small portion of it be taken up with

164 DROPS OP WATER.

the water, the animal will adhere to it by its tail,
and display its wheels. I kept them in the same
mug for ten years.” This transparent creature
is fusiform, or spindle-shaped, tapering gra-
dually to the foot when expanded, but when
contracted it is thick, and the head and tail dis-
appear within the body ; the joints are not visible
when the creature is expanded, but when con-
tracting, their curious conformation is seen, and
the method of sliding one within the other clearly
observable. The foot, or tail, has six processes,
placed two and two at the joints. The upper ex-
tremity of the body has a pair of wheels, distinct
from each other, and of very wonderful construc-
tion ; when the wreaths of cilia which form them
are in full motion, they produce strong currents

ROTIFER.

165

t

in the water • and small particles of food are
brought within reach of the mouth, and swal-
lowed rapidly, to be ground up by the powerful
jaws placed below. There are two red eyes,
and a long process, which is considered as the
respiratory tube; these form what may be
termed the head, and they can all be with-
drawn at pleasure. The mode of progression is
by swimming rapidly, with the wheels expanded,
and body and tail stretched out, or, when moving
on weeds, &c., by using first the head and then
the tail, so as to form a kind of step; — when
feeding, it attaches itself by the tail, and, ex-
panding its wheels, seems to be happily and
busily employed. It is an amusing sight to
watch the current thus made, particularly if a

166 DROPS OF WATER.

little paint be put into the water; but I can
imagine no sensation more wretched to those
unfortunate little creatures, that come within
the vortex caused by these powerful wheels,
if they are aware to what it leads : they are
often whirled round many times, before they
either enter the mouth, or are so happy as to be
refused by the monster. I have seen them re-
peatedly, when beyond the influence of the cur-
rent, fall down, as if spent with fatigue or fright.
The eggs of the Rotifer can be seen distinctly
in different stages of maturity within the body,
and even the wheels of the young ones have been
seen in motion by some observers. This species
increases most rapidly ; from one individual a
million may be produced in ten days. They are

ROTIFER.

167

found both in sea-water and in infusions, as well
as in water which abounds in plants ; and they
have been observed in the cells of Sphagnum
ohtusifolium , which is a kind of moss, with
whitish leaves, growing in bogs and swampy
places. Rceper says, that the cells have openings
into the water, so that the animalcule may creep
in, but he also relates that he has found them
in the cells of parts of the plant not exposed to
the water. If the cells of the Sphagnum are
open at times, I can easily imagine that the
Rotifer will creep in, for my own observation
nearly proves that they will occupy any small
cavity, where they perhaps may feel that they
may feed in safety. I founded my opinion upon
the following facts, which I observed last spring

168 DROPS OF WATER.

/

frequently. I flattered myself for some time that
I had discovered a new species, but after re-
peated observation, I came to the conclusion
that it was in all probability the U. vulgaris , or a
species of Philodina living as I may say in retire-
ment. It appeared to me, that these specimens
had placed themselves in the empty cases of the
Floscularia , but they were invariably so much
covered with extraneous deposit, that I could not
decide the matter satisfactorily. The wheels, jaws,
and respiratory tube alone, were visible beyond
the edge ; and as it expanded and contracted
within the case, in a similar manner to the Flos-
cularia, I at first thought it was, like that ani-
malcule, attached to, and the architect of, the
case ; but as I never saw any of the specimens

ROTIFER.

169

leave the snug retreat in which they had fixed
themselves, even though I watched many ex-
amples, I still somewhat doubt, especially as
there were no specimens of R. vulgaris swimming
about. These specimens might prove to be
species of Philodina , though I think those ani-
malcules, as well as the Rotifer , have never been
observed to form cases.

I have mentioned the tenacity of life in this
animalcule, in the Introduction, and would advise
the experiment to be tried by all interested in the
truth. An instance of revivification of an equally
small creature may be mentioned. The disease
in corn, called ear-cockle, or blight, is caused by
a very minute eel-like animal, which fills the seed,
and remains dormant for some years, until the

Q

170 DROPS OF WATER.

grain is opened and placed in water, then thou-
sands of these minute creatures make their ap-
pearance, and after some time revive, and swim
about. I have tried this with corn four years
old ; there is, therefore, nothing unlikely in the
statement that the Rotifer may revive after being
apparently dried for a length of time.

Actinurus Neptunius (Drop IV. fig. 12). — This
extraordinary and elegant creature greatly re-
sembles the Rotifer vulgaris , but is easily distin-
guished by the extreme length and wonderful for-
mation of its tail, which, when at the full stretch,
has a most striking appearance. The joints shut
one within the other, like the tube of a telescope,
and this action the animalcule is constantly re-
peating when searching for food : it fixes the tail

ACTINURUS. 171

to some substance, and then stretches it and
the body out to an immense extent, displaying
its rotatory organs, and feeding for an instant,
it then contracts, and pursues the same course
in a contrary direction. The body is more
slender than the Botifer ; it has two eyes, and the
chewing apparatus is very distinctly seen. The
tail has three points, or toes, and two little horns
attached to one of the joints : these expand,
when the parts are stretched out, but as this form
would prevent the joint above that to which
they are attached, sliding over them, they have the
power of lying flat, and the tube closes without
any impediment. This interesting animalcule is
not so common as the individuals of the last
genus, though frequently found with them.

172 DEOPS OF WATER.

Philodina erythroph thalma is another slender-
bodied animalcule, with a tail resembling the
Rotifer, and two wheels as rotatory organs : it is
found in vegetable infusions. P. roseola is flesh-
coloured : Ehrenberg says that this species lays
its eggs in heaps, and remains with the young for
some time, forming one family. P. aculeata is
distinguished by having soft spines upon the
body, which give it a remarkable look ; the respi-
ratory tube has a thickened end.

We now come to the last family into which
these little creatures are divided ; it is called
Brachioncea, and consists of several genera, con-
taining species of great beauty. They have a
lorica somewhat resembling the shell of a tor-
toise ; the rotatory organs are divided into more

N0TEUS. 178

than two parts, though the two at the sides seem
more particularly used as active organs. One
genus, Anurcea , has no tail or foot, the others
have a powerful instrument of this kind ; three
of the genera carry their eggs attached to the
outside of the body, giving them a very curious
appearance, but seeming not to impede their
progress through the water.

Noteus quadricornis (Drop IV. fig. 13) is a very
fine and interesting animalcule, of considerable
size, and, being broad and flat, soon attracts the
eye. The lorica is nearly round, much flattened,
rough, and on one side seems divided into com-
partments ; it has also two spines near the tail,
and four at the head ; the whole very transparent,
allowing the body to be seen within. There

174 DROPS OF WATER.

is no eye. The head is formed of a two- wheeled
organ, and a ciliated part divided into three lobes ;
with these the creature forms a strong current
in the water, drawing towards it many small
objects floating past, and occasionally selecting
one, which then enters the mouth, where the jaws
are ready to receive it. I have frequently seen
it swallow small Polygastrica , one after the other,
very rapidly. The tail, which is thick and very
powerful, projects from the lorica, between the
two spines at the base : it grasps a stalk with
this forked tail, and then, raising the body, ex-
tends its wheels, and feeds with avidity. It occa-
sionally jerks the body backwards and forwards
with great force, still holding by the tail, as if it
were greatly excited, showing the strength of its

ANURiEA.

175

muscles, and its health and vigour. It is fre-
quently seen with eggs attached to the body, and
is often found in water where decayed leaves and
Algae are abundant.

Anurcea squamula (Drop IV. fig. 15).— There
are many species of this genus, but they are all
known by being without a tail or foot, and most
of them carry their eggs attached to the body ;
they possess an eye, and swim very rapidly. The
lorica of the species squamula is smooth, rounded
at the base, having horns in front, rather flat
when seen sideways, and slightly curved : it has
usually one egg of considerable size attached.
A. stipitata has the lorica nearly square, with six
spines in front, and one at the base, which might
be taken for a tail, but it is quite rigid.

176 DROPS OF WATER.

The genus Brachionus has a lorica like a tortoise-
shell, and both front and base are spined; in
some species it is smooth, in others rough. The
rotatory organs are double, and the tail or foot is
forked; the eggs are attached, and sometimes
as many as ten are thus carried about. It has
a single eye. B. poly acanthus (Drop IV. fig. 14)
is one of the most common. It has a smooth
lorica, with two very long spines and three
short ones at the base, the upper part having
many ; the wheels do not extend much beyond
the edge of the lorica : the tail is strong, and
powerfully grasps any substance in the water.
B. militaris has the lorica rough, four spines at
the base, and twelve long ones at the upper end.
B.urceolaris is often seen in vast numbers in

PTER0D1NA. 177

fresh and brackish water : it has a smooth lorica,
round at the base, and six short spines in front ; it
is nearly as large as Noteus quadricornis. B. ru-
bens is similar in shape, but the body is reddish.

Pterodina patina (Drop IY. fig. 16). — This is
one of the most delicate, beautiful, and transpa-
rent of these lovely little beings. When viewed
with a magnifying power of 250 diameters, it
appears about the size of a sixpence, the lorica
nearly round, and having no processes like the
other genera of this family : it is exceedingly
flat, and so transparent that, with the exception
of some parts of the body, it is difficult to see this
animalcule if the water is very clear. The ro-
tatory organ is double, forming two wheels ; the
tail, or foot, is thick, rather clumsy, and furnished

i.

178 DROPS OF WATER.

with a disc at the end, by which it holds to sub-
stances : it proceeds from near the centre of the
under surface of the lorica, and is clearly seen
when the creature turns on its side, which it does
frequently in swimming. It has two eyes.
When alarmed, it withdraws its wheels into the
case, as well as the tail, nearly, and lies quite still
for a moment, soon, however, becoming active
again, and then nothing can be more inter-
esting than the quiet movement and elegant
appearance of this animalcule. It is not com-
mon, but found sparingly in summer, principally
among Lemna ; I once found it as early as
February, but in small numbers. P. ettiptica
has a lorica of an elliptical form. P. clypeata is
found in sea- water: it has an oblong lorica,

LARVjE, ETC. 179

shaped somewhat like a vase, and smaller than
the other species.

Many other creatures of small size, besides
Infusoria, will of course be met with in water,
but they will soon be recognized as belonging to
other classes of the animal kingdom. Several
long, worm-like creatures, are the larvae of the
gnat and midge, or perhaps those of the dragon-
fly or Tipula. There are several species, also, of
Vibrio, which will soon be distinguished if the
one found in sour paste is known. Then there is
a pretty and very lively little creature frequently
seen where duckweed abounds, the Lyncius splice -
ricus. It is enclosed in a round, transparent
shell, the only projection being a beak, and the

180 DROPS OF WATER.

occasional protrusion of a foot ; the eyes are black :
it feeds on animalcules, and pursues its prey
with great activity. The Cyclojps quadricornis,
or water-flea, is larger than the Lyncius , and has
branching horns, or arms : it is very transparent,
and the lungs may be seen clearly in motion : it
has but one eye. In some species, of which
there are several abounding in stagnant pools,
the eggs are enclosed in a membrane, and at-
tached to the outside of the body. The Cypris
is another curious creature, often found in great
numbers : the body is enclosed in a kind of
horny bivalve shell, which is not transparent;
horns, or arms, are occasionally protruded from
an opening, by the action of which it moves
quickly. Their shells are found in myriads in

CONCLUSION. 181

a fossil state. The Amymone satyra may be ob-
served in clear water, and is a beautiful object for
the microscope : it is rather oval in shape, with
four legs, two antennae, and one bright red eye,
the whole body tinged with yellow, and very
transparent; it moves quickly, but in jerks.
These are a few only of the interesting objects
which may be observed in water, besides ani-
malcules.

I have now described as many genera and
species of these exceedingly beautiful little beings,
as the young student will probably be able to
find in the course of several seasons ; but with
diligent search, and frequent use of the micro-
scope, nearly all these may be seen, and admired,

R

182 DROPS OF WATER.

in any neighbourhood, particularly as water may
be conveyed (with care) even from a distance.
I believe it is considered safer to fill the bottle
in which the water is carried full to the cork, as
the motion is then trifling, for the shaking of
a half-filled bottle kills all the delicate kinds.
When a drop of water, tolerably full of life, is
placed under the microscope, all seems confusion
to the inexperienced eye, the varied forms and
rapid movements cause bewilderment in the mind
of those who really wish to make a study of the
names, habits, and peculiarities of these living
atoms; but after some use of the glass this
feeling subsides, and some one specimen attracts
the attention, its shape is remembered, refer-
ence is made to the illustrations, and there some

CONCLUSION. 183

species similar in form will probably be traced ;
then, by referring to the description, the name of
the genus or species may be found, with its cha-
racteristics and habits. A species, when once
impressed thoroughly on the mind, and its name
remembered, soon ceases to attract attention,
however frequently it may pass, if the eye is
fixed on an animalcule which is new to the ob-
server ; thus the confusion is soon lessened, and
each drop at last produces so many old friends,
that we have leisure to watch their movements,
and be amused with their varied habits of life,
and extraordinary modes of obtaining food. To
those fond of watching the sports and movements
of creatures of a larger growth, these little atoms
will be never-failing sources of amusement ; and

184 DROPS OF WATER.

even should the observer only seek to wile away
an hour, the objects are always novel and full of
interest ; but to those who delight in examining
the wonderful works of creation, there can be no
greater source of pleasure than the possession of
a good microscope, and the power of beholding
minute beings, all of which are so totally dissimilar
to those seen without this assistance. The gift of
a microscope to a young inquiring mind, may,
therefore, prove one of the purest sources of quiet
pleasure, and lead to the cultivation of a taste for
natural history in general, in the study of which
so many hours may be profitably spent, which
would, perhaps, otherwise be wasted in trifling
or idle amusements. Allow me, then, to press
this fascinating pursuit, not only on those who

CONCLUSION. 185

are already lovers of Nature, but on those who
are seeking for amusement and occupation. I
can promise with some confidence that they will
at all events not meet with disappointment, and
will with more probability discover that a never-
failing source of delight and interest has been
opened to them, —a new and almost unknown
region, peopled with minute beings whose beauty
cannot be surpassed or described ; — -

Where, even in a water drop,

These wondrous creatures revel, filling up
The seeming void of nature ; even as planets,

By the naked eye unseen, perfect
The glorious firmament.

ALPHABETICAL LIST

OF

GENERA AND SPECIES.

Page.

Acineta mystacina . . . . . . 79

tuberosa ....... 79

Actiniums Neptunius (Drop IY. fig. 12) . . . 170

Amoeba diffiuens . . . . . ■ . 112

princeps (Drop II. fig. 12) . . . Ill

radiosa ........ 112

verrucosa ....... 112

Amymone satyra . . . . . . .181

Ankistrodesmus falcatus . . . . . 69

Anursea squamula (Drop IY. fig. 15) . . 175

stipitata ....... 175

188 ALPHABETICAL LIST OF

Arcella aculeata ......

Page.

. 113

dentata

. 113

vulgaris

. 113

Arthrodesmus convergens (Drop I. fig. 6)

65

incus

65

Astasia hsematodes (Drop II. fig. 9)

. 104

nivalis

• 105

pusilla

. 105

Bacillaria cuneata (Drop I. fig. 18)

75

paradoxa ......

74

vulgaris (Drop I. fig. 17)

74

Bacterium .......

. 103

Bracliionis militaris

. 176

polyacanthus

. 176

rubens ......

. 177

urceolaris

. 176

Bursaria truncatella (Drop III. fig. 7)

. 132

Callidina elegans ......

. 161

Carchesium polypinum (Drop III. fig. 3)

. 126

Chsetonotus larus .....

. 143

Chlamidomonas pulvisculus ....

99

Closterium acerosum (Drop I. fig. 8)

67

Dianse (Drop I. fig. 9) ...

68

GENERA. AND SPECIES.

189

Page.

Closterium moniliferum ....

67

— — setaceum (Drop I. fig. 10)

68

Colacium. stentorinum .....

. 108

vesiculosum .....

. 108

Cosmarium margaritiferum (Drop I. fig. 4) .

64

Cothumia imberbis (Drop III. fig. 5)

. 129

Cyclidium glaucoma .....

. 115

Cryptoglena conica .....

87

Cryptomonas

86

Cyclops quadricomis .....

. 180

Cypbidium aureolum .....

. 113

Cypris .......

. 180

Desmidium quadrangulatum ....

61

Swartzii (Drop I. fig. 1)

60

Difflugia proteiformis (Drop II. fig. IB) .

. 112

Dinobryon sertularia (Drop II. fig. 11) .

. 109

Distigma tenax . . .

. 108

viride ......

. 108

Doxococcus iuequalis

85

pulvisculus

85

— — ruber (Drop II. fig. 2) .

85

Echinella

77

Epistylis anastatica .....

, 127

190 ALPHABETICAL LIST OP

Page.

Epistylis digitalis 127

grandis 127

nutans ....... 127

parasitica 128

plicatilis ....... 126

Euastrum insigne 63

oblongnm (Drop I. fig. 3) . . . 63

Euchlanis triquetra . . . . . .157

Eudorina elegans (Drop II. fig. 7) . . . . 97

Euglena acus 106

longicauda 106

pleuronectes 106

pyram ....... 106

sanguinea (Drop II. fig. 10) . . . . 105

viridis ....... 105

Euplotes cliaron (Drop III. fig. 9) . . . . 138

patella 138

Eloscularia ornata (Drop IV. fig. 1) . . .145

proboscidea ..... . . 145

Eragilaria grandis 75

rbabdosoma (Drop I. fig. 1 9) . . . . 75

Glenomorum tingens . . . . . . 85

Gompbonema . . . . . . . 77

GENERA AND SPECIES.

191

Gronium glaucum ......

Page.

93

• — — pectorale (Drop II. fig. 5)

93

G-yges . . . .

89

Iclithydium podura

. 142

Lagenella euchlora .....

87

Lepadella ovalis (Drop IV. fig. 8) .

. 155

Limnias ceratophylli (Drop IV. fig. 2) .

. 149

Lyncins sphsericus

. 179

Mastigocerca carinata (Drop IV. fig. 9) .

. 156

Melicerta .

. 150

Meridion vernale .....

76

Metopidia lepadella .....

. 160

Micrasterias denticulata (Drop I. fig. 2) .

62

Microcodon clavus (Drop IV. fig. 3)

. 150

Microglena ......

84

Monas crepusculum (Drop II. fig. 1)

83

Navicula acus (Drop I. fig. 16)

74

— — ampliisbsena (Drop I. fig. 15)

74

viridis (Drop I. fig. 14)

74

Notommata longiseta (Drop IV. fig. 4) .

. 151

Nolens qnadricornis (Drop IV. fig. 13) .

. 173

Opercularia ......

. 128

Pandorina morum (Drop II. fig. 4)

90

192 ALPHABETICAL LIST OF

Paramecium aurelia (Drop III. fig. 8)

Page.

. 186

Pediastrum Napoleonis (Drop I. fig. 12) .

69

pertusum (Drop I. fig. 11) .

69

Peridinma .......

. 115

Philodina aculeata .....

. 172

erythrophthalma

. 172

roseola ......

. 172

Polyarthra trigla (Drop IY. fig. 6) .

. 154

Polytoma uvella ......

84

Prorocentrum micans

87

Pterodina clypeata

. 178

elliptica ......

. 178

patina (Drop IV. fig. 16)

. 177

Rattulus lunaris (Drop IV. fig. 7) •

. 155

Rotifer vulgaris (Drop IV. fig. 11)

. 162

Salpina mucronata (Drop IV. fig. 10)

. 158

Scaridium longicaudum ....

. 153

Scenedesmus quadricaudata (Drop I. fig. 13) .

69

Sphserosira volvox .....

. 100

Spirillum

. 104

Spirotsenia

68

Staurastrum cuspidatum (Drop I. fig. 7)

66

Stentor cseruleus

. 119

GENERA AND SPECIES.

193

Stentor igneus

Page.

. 119

Miilleri .....

. 118

niger .....

. 119

polymorphus ....

. 119

Boeselii (Drop III. fig. 1)

. 118

Stephanoceros Eichhornii

. 147

Stephanops lamellaris ....

160

Synchseta pectinata (Drop IY. fig. 5)

. 152

Syncrypta volvox ....

94

Synura uvella (Drop II. fig. 6)

96

Trachelius anas .....

. 132

Trachelocerca olor (Drop III. fig. 6)

. 131

Trachelomonas cylindrica

88

volvocina (Drop II. fig. 3) .

88

Trichodina

. 119

Urocentrum turbo ....

. 119

Uroglena volvox .....

97

Uvella glaucoma .....

83

Vaginicola crystallma (Drop III. fig. 4) .

. 129

decumbens ....

. 129

Yibrio ......

. 103

Yolvox aureus

. 102

globator (Drop II. fig. 8)

102

194 LIST OF GENERA AND SPECIES.

Page.

Yolvox stellatus . . . . . . .102

Yorticella campanula . . . . . ,125

convallaria (Drop III. fig. 2) . . . . 120

Xanthidium aculeatum . . . . . . 65

armatum (Drop I. fig. 5) . . . . 64

Zoothamnium arbuscula . . . . .128

Printed by Reeve and Nichols, 5, Heathcock Court, Strand,

POPULAR

BRITISH ENTOMOLOGY;

comprising a familiar and technical description of the Insects most common to
the British Isles.

BY

MARIA E. CATLOW.

“ Miss Maria Catlow’s judiciously executed ‘ Popular Introduction,’ with ex-
cellent figures of the commoner species, for the use of young beginners.” — Mr.
W. Spence, Address to the Entomological Society.

“ Miss Catlow’s Popular British Entomology contains an introductory chapter
or two on classification, which are followed by brief generic and specific de-
scriptions in English of above 200 of the commoner British species, together
with accurate figures of about 70 of those described. The work is beautifully
printed, and the figures for the most part nicely coloured, and will he quite a
treasure to any one just commencing the study of this fascinating science ; in
fact we know of no more acceptable present to the young student of Entomology.”
— Westminster and Foreign Quarterly Review.

In one vol. royal 16mo; with sixteen plates of figures.
10«$. §d. coloured.

POPULAR

BRITISH ORNITHOLOGY;

COMPRISING ALL THE BRITISH BIRDS.

BY

P. H. GOSSE,

Author of c The Ocean/ ‘ The Birds of Jamaica/ &c.

“ To render the subject of ornithology clear, and its study attractive, has
been the great aim of the author of this beautiful little volume. It contains
descriptions of all our British birds, with the exception of those which may be
considered in the light of stragglers, and which are not likely to fall in the
way of the young naturalist, for whose use this work is intended. It is em-
bellished by upwards of 70 plates of British birds beautifully coloured.” —
Morning Herald.

“We can answer for this compact and elegant little volume being beautifully
got up, and written in a manner likely to attract the interest of the youthful
student.” — Globe.

“ This was a book much wanted, and will prove a boon of no common value,
containing, as it does, the names, descriptions, and habits of all the British
birds. It is handsomely got up, and ought to find a place on the shelves of
every book-case.” — Mirror.

In one vol. royal 16mo, with twenty plates of figures.
10s. Qd. coloured.

New Edition of Dr. MantelVs ‘ Pebble ,’ with Portrait of the Author.

Considerably enlarged, pp. 102, four coloured plates, twenty-eight woodcuts,
and Portrait of the Author engraved on steel, price 5s.,
handsome cloth, gilt edges,

THOUGHTS ON A PEBBLE.

[EIGHTH EDITION, '.]

BY

GIDEON ALGERNON MANTELL, LL.D., E.R.S.,

Vice-President of the Geological Society, &c.

“ This elegant little booh, primer-like in size, and illustrated by fine coloured
plates and wood-engravings, serves still to convey some of the grandest truths
in Geology. After what we know of the accomplished author, we might well
expect, when he picks up and describes a pebble, and gives us its history, that
we should find

‘ books in the running brooks,

Sermons in stones, and good in everything.’

It is almost superfluous to add, that the style is lucid, eloquent, poetical, and
philosophical, for all these attributes are combined in Dr. MantelFs waitings.
The elegant form of the little book, its snowy paper, excellent type, and pictured
engravings and cover, recommend it to the eye of taste ; while to the philosopher,
as well as the pupil, it presents truly a first lesson in Geology, and cannot be
perused without both pleasure and profit. It has passed through seven editions,
and we wish they may be repeated as long as the stars glow, or the waters
flow.” — American Journal of Science.

“ I have just procured a little work for my young pupils, a most delightful
introduction, entitled ‘Thoughts on a Pebble, or a Eirst Lesson in Geology,’
by Dr. Mantell, and I must request you to read it ; for although it does not
consist of more than thirty pages [increased in the present edition to upwards
of a hundred] it will expand to your view a new world that will astonish and
delight you.” — Philosophy in Sport.

EPISODES OF INSECT LIFE. First Series.

Crown 8vo. Beautifully illustrated and bound, 1 6s. Coloured and
bound extra, gilt back, sides, and edges, 21s.

“No one can have observed the habits of Insects without feeling how rich a
field they afford for the exercise of the imagination, in giving to their complicated
actions the motives and attributes of humanity : and the object of the writer of
‘ Episodes of Insect Life ’ is to lay the less common fields of entomological re-
search under contribution, for the purposes of amusement and instruction. We
have seldom been in company with so entertaining a guide to the Insect World.
Few merrier or wiser companions could be submitted to our fire-side at this
genial season. We should, however, give an imperfect idea of its merits if we
did not speak of its beautiful illustrations and amusing tail-pieces. At the head
of each chapter is a well-executed engraving of some one or more of the insects
described, in their natural attitudes and characters, whilst the tail-pieces consist
of humanized portraits of the same creatures, engaged in some of the occupations
with wrhich the writer has endeavoured to enlist our sympathies.” — Athenceum.

EPISODES OF INSECT LIFE. Second Series.

Crown 8 vo. Beautifully illustrated and bound, 16s. Coloured and
bound extra, gilt back, sides, and edges, 21s.

“ This second series of £ Episodes ’ is even more delightful than its predecessor.
Never have entomological lessons been given in a happier strain. Young and
old, wise and simple, grave and gay, cannot turn over its pages without deriving
pleasure and information.” — Sun.

EPISODES OF INSECT LIFE. Third and

concluding Series. Crown 8vo. With an index to the preceding
Volumes. Beautifully illustrated and bound, 16s. Coloured and
bound extra, gilt back, sides, and edges, 21s.

“We have looked forward to meeting our old friend with anticipations of en-
joyment, remembering the pleasant hours we passed with her in former years.
Nor have our expectations been disappointed : our gossip is as merry, as in-
structive, as wise as ever.” — Athenceum.

“ A work on insects, written in true insect fashion — brisk, gay, lively, basking
in the sunshine, with a series of irregular and often graceful movements. Each
of the chapters of the hook treats of a thousand things besides the anecdotes,
habits, and peculiarities of the insect to which it is devoted, and all done in a
piquant and pleasing style, with a true tone of the subject, and a warm appre-
ciation of natural beauties. The book is ornamented with a series of insect cari-
catures— the quaintest and most ingenious woodcuts imaginable.” — Atlas.

• '

v'v'

rv, i4nu*vTOft£

iipi^i

m0m

M fflm 0