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LE S S 0 N S 0 N SHE L L S,

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11. \ K\' . \ IH > l :" I \' E RS ITY.

IN A PESTALOZZIAN SCHOOL,

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BY TIIE

AUTHOR OF "LESSONS ON OBJECTS."

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ILLUSTRATED BY TEN PLATES, DRAWN FROM NATURE.

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NEW-YORK:

PETER HILL, 94 BROADWAY.
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\tlill~:FACE.
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Quin ipeis doctoribus hoc esse curre velim, ut teneras adhuc mentes mote nutricum mollius alant, et satiari veluti qnodam jucundioris discipline lacte patiantur. Erit illud plenius interim corpas,
quod mox adulta retas adsuingat. Hine cpes roboris.

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v·an Norden, Print.

Sleight &

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Q.UJNTILIAN .

' LESSONS on Shells' may be considered as a continuation of' Lessons on Objects;' the principles of
teaching illustrated in that little work are here applied to an important and interesting branch of Natural History. It is, like its unpretendin(J' predecessor, a transcript of the actual labours of the classroom; and friends who have visited the school,
may retrace in the printed work the process of
which they were witnesses. The end for which
it is now laid before the public is not that it may
serve as an instructive and entertainin~ volume to
be placed in the hands of children ; this end is sufficiently attained by several works of acknowledged
merit, which, in order that the subject may be
more familiarly handled and more vividly conceived,
represent an imaginary group of pupils conversing
and receivin~ instruction. The object my sister
has proposeo .to herself is to place a ,-olume in 1he
Teacher's hands which shall help him to re-act
with his pupils the scenes that are here described.
It is not a drama offered for perusal in the r.loset,
but a manager's copy commended to the conductors
of other thea tres ol education, to enable their lilliputian corps dramatiques to assume the same characters, play the same parts and I will not say,
"fret their little hour upon the stage," but enjoy
the genuine delight of intellectual activity judi~
ciously directed.

iv

v

PREFACE.

PREFACE.

A want of order and arrangement in the early
part of' L essons on qbjE;,~\s ' t1as been alleged as a
blemish in that work ; '!Jt'd, ·ln11loint of fact, its misce llaneo 11s character' f'•M .ll ~\A-lf1ie P. feature, as better sui tc t! to the intl!lleptu;il state of the pupils.
Their first step sho uld ·be·1thbl examination of objects as nature presents them, or rather as they see
them in nature, that is, either as insulated or as
associated only by accidental connection: When
ideas are formed and correct expressions familiarized, the business of classification commences, the
lessons assume a more scientific character, and the
pupils are prepared to enter on the province of Natural History. The training, then, which 'Lessons
on Objects' will have supplied for commencing
'Lessons on Shells,' will consist principally in the
impro ve d faculty of observin"' natural -features, in
th e possession and command ';;fa small vocabulary
of scientific terms, in the habit of classification, and
in the practice of giving a written summary of the
knowledge required.
Several circumstances concur to recommend
concholog-y as the first branch of Natural History
to be studied by younger pupils. Shells are of
themselves interesting, from the peculiarity of their
forms ant! the varit>ty of their colours ; their chac
racteristics are simple and present themselves readily to the eye, and a variety of interesting information may be given respecting the animals which
inhabit them. Added to this, the greater part of the
specimens may be procured at little expense, may
be easily preserved , and therefore continually reproduced to the class, and besides may, without
fear of damage, be committed to the careless hands
of the youngest students.
.
It will however, I know, be objected by stanch
anti-reformers in 'e ducation, that improve the mode
of teaching Natural History as you will, you but

, teach better that which had better not be taught
at all; for that wha{.e:v~r\'iJlf.ipges the time given
to classical instructi'on, . weakens the nerves and
sinews of the mind; 13.l!M but ~&bases the Corinthian
column of ancient !or~ ?rif:\l~~ducing the barb_arous
ornaments of mod ern science. My answer is, we
do not propose to devote a large portion of time to
Natural History in ordinary cases, and even this
will be taken principally during those early years
when very little real progress is made in Gree k or
:::...a tin. Every age has its intellectual _as. ~e ll as
its moral claims, and though the stern discipline of
early classical, instruction may offer some ad vanta"'es, still the hours devoted to the abstractions of
gr~mmar, and the puzzling out ideas which have
no prototype in the child's mind through the dark
mist of a lan(J"uaae little akin to his maternal
tongu.e, present ve°ry meagre food to that understanding they are supposed to strengthen. If the
child must lisp in Latin, let him do so; let his first
Gradus ad Parnassum be through the quagmires at
its base; the few choice spirits that mount the
summit may, perhaps, trea d it with firmer step,
and enjoy the prospect with keener reli s~; but that
step will not he the less firm, nor that relish the less
keen, because a daily hour was abstracted for 'Lessons on Objects,' or' Lessons on Shells.' Not only
are the sciences so linked together that each gives
each a double charm, b11t the faculties of the mind
are so constituted, as that the vigour of each is
promoted by the due development of the rest. And
there is a harmony as truly existing in a properly
educated mind, as in a well formed and well exercised body, thou~h the harmony of the former may
not be so easily discerned as that of the latter.
As years advance, the study of Natural History
may be confiried to those who manifest a peculiar
taste for it, or who exhibit little disposition for clas-

vi

PREFACE.

sical p1;1rsuits. For, as 'every age has its intellect- ·
ual claims, so also had .tliJtvy\ uradc of talent. The
schools of the hi~prsJ ri;1Jl4\ion have generally
been conducted too ex'cTu~iv~l'V lo the arlvantad-e of
the superior class oftnlind:l / \i'he fine porcelai;' has
been beautifully moulded and delicately pencilled,
but the coarser clay has been almost entirely neglected. Yet many a young man who will never
shine in the Senate House or the Schools, may yet
pursue Natural History with success, and find in
such pursuits improvement for his mind, a refuge
from ennui, and a substitute for sensual pleasures.
There is much truth as well as benevolence in a remark I once hea rd from an amiable coadjutor of
Pestalozzi ; "Tout terrain est hon si ,!'on sait le
cultiver."
Much of the instruction thus communicated, will
doubtless fade from the mind; but not _with it will
pa~s a way all the benefits arisin.,. from these studies. In after years they may '6e recommenced
with greater facility, in consequence of the early
training, and every incidental reference to these
subjects, which conversation or litera ture rhay
present, will be more readily seized, and more
clearly comprehended. And may it not be ?-1\"ticipated, that through the judicious introdii.ctiqn· of
these branches of education into our schools, the
latent powers of genius may be kindled, and talents
elicited that shall push forward the limits of science,* and force the Proteus nature to reveal still
more of her secret truths?
C . .M:uo.

In drawing out 1 Lessons on Shelu,' the following works ha;e
been consulted, and extracts made from them.

Burrows' Elements of Conchology.
Turton's Conchological Dictionary.
Turton's Bivalve Shells of the British Isles.
·l \fawe's Conchology.
Montagu's Testacea Britannica.
Fleming's Philosophy of Zoology.
Lamark's Histoire N aturelle des ammaux sans
Yertebres.
The Conchologist's Companion.
Shaw's Nature displayed.
Sowerby's Genera of R ecent and Fossil Shells.
Dillwyn's Descriptive Catalogue of Recent
Shells.
The plates whlch illustrat e this work have been drawn from
specimens actually presented lo the class : they are intended
as an assistant to the teacher, but not as a substitute for the·
shells themsch-es in the instruction of pupils.

Cheam, ·June 15, 1932.
• In confirlriation of this idea, it may be stated, th at a very in·
geniou~

improT"em ent of th e di ssecting microscope, which has
merited a rewax:d frC'lm the Socie ly of Arts, has been invented

by a very young person brollg ht up on th ese principles. I have
the more unmixed pleasure anti hone!:lt pride in mentioning this

fact, as it refers not to a pupil of my own, but to one educated at
Stanmore.

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LESSONS ON SHELLS.
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ON THE Mfll~-1\V~9/\y

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Teacher. Do you know what these things are
which I have brought in as the subject of our
lesson to-day ?
Child. They are shells.
Tecicher. Describe to me what you mean by
a shell.
Child. Oh, a shell is that which covers a
snail.
Teacher. Very true ; a snail has a shell, but
in saying this you do not explain to me the nature of a shell. "\;Vhen you attempt to describe
any thing, you should give such an account as
would instruct a person altogether ignorant on
the subject. Try again, and tell me what a
shell is.
Child. A shell is a hard covering or house
belonging to animals resembling slugs.
Teacher. Of what use do you suppose shells
to be?
·
Child. They must be a defence and protection to the animals which they cover.
Teacher. Yes: shells arc the hard coverings
of certain animals called. mollusca; a name

10

LESSON I.

derived from mollis, the Latin for soft; if you
call to mind the animals enclosed in these cases,
you will not fail to observe how applicable this
term is to them. Give me some example to
prove that this name is well chosen.
Child. "I'll~ s'nh.tt:has a very soft fleshy body.
.Teachery. 1• f f-.if• p•Jl~ : ll'\e mollusca in this respect
are all alike. ~ l:i1\ve brought you some to examine; look 1al · 't1i~ih 1 well, and try and discover
the characteristics which distinguish them from
other animals. Here are a snail, an oyster, a
muscle, a slug.
Child. I am sure that we shall not be able to
say much about such animals as these, they are
so shapeless and uninteresting in their appearance.
Teacher. Do not form so hasty a judgment.
I hope soon to convince you that it is your ignorance alone which causes you to view them .with
indifference. There is not, indeed, any part of
the creation which you can study, that will not
repay you for your labour; and when you become better acquainted with the different kingdoms of nature, you will experience an increased
pleasure in your walks; and objects that you have
hitherto passed heedlessly by, will rivet your
attention by the wonders they unfold to you ;
but my great desire is, that you should trace in
all these things, the hand of an almighty and
beneficent Creator. When you are struck with
the beautiful arrangement in a plant, with the
means of defence possessed by one animal, and
the sagacity displayed_ by another, consider

MOLLUSCA.

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·which you ought most to admire, the instrument
or Him who so well fitted and prepared the instrument for the work to which it is appointed. Now,
suppose that you have yourself made or done
·any thing very nicely and with great p~s for a
·friend, would you feel satisfied, or think it. just,
if, whi!-e your performance was admired, you
were forgotten ?
Child. I should consi?er such conduct very
unfair. \
Teacher. And what lesson do you suppose
that I wish to teach you by drawing your attention to your own feelings when your industry
and ingenuity have been thus overlooked?
Child. That when we are struck . with the
beauty and utility of any of God's works, we
should praise him for his wisdom, and thank him
for his goodness.
Te(leher. It is with such feelings that I wish
you to study Natural History, and it would then
prove a very delightful and profitable .employment. 'if You must now return to the consideration of the animals before you. Examine them
• It is most important in giving instruction in Natural History,
early to nccm;to111 chih lr ~ 11 to r ccogn i ~e the God of nature in his
. works. If God be robbcU of his gl ory , how ca n we anticipate a
blessing on our labours? Ha s not experience proved, that the
study of the wonders of creative wisdom does not lead the natural
heart to the Creator? ls it not notorious, th at among the followers o( science is continually seen the practical, if noc the avowed
atheist. Let this be a beacon to the Christian instructor, and Jet it
be his careful endeavour to g uard against the t~tal error of speaking of God's works independ ently of him . As we - are caJled upon
., t to walk by faith, and not by sight, it is essential to lead children to
, -< see God in all things, and to trace Him who ia himself iuvisible in
· ~ thol!le outward manifestations of his power and goodnesa, which are
within the reach of their observation.

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LESSON J.

carel\1lly--exercise .your different se!1ses ~pon
them-mark the various parts of their bodiesconsider to what use each part is likely to .b e
destincd.:,,-and reflect upon what you know of
their habits. By using well your sense and your
judgment, you will be able to find out m~ch for
yourselves. · '\'Vhen you are at the. sea-s1d_e, or
out at sea, you may collect facts illustrative of
the history of these animals.
.
. ·
Child. That would be exceedmgly mterest-

ing.

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Teacher. Yes, it would; but you nee not
·wait for such opportunities. Rivers, and even
the garden, will afford you Sj)ecimens for ob~er­
vation : but what have you now to do 1
Child. To examine the animals before us, to
use our senses upon them as we did in our lessons on objects, to name their parts, and the
uses of their parts as far as we know them.
Teachei·. Yes ; I wish you first to observe
these creatures attentively ; and that you may
discover readily what is peculiar to. them,. rou
must in your own minds compare their qualities,
parts, and habits, with what you know of o~~er
' animals. First, however, tell me some qualities
that appear to you to be common to all the mollusca.
Child. Their bodies are soft, fleshy, moist,
and cold.
.
.
Teacher. Yes, you remember their name is
given to · them from their softness. Observe
also the action of a snail when an enemy
approaches.

MOLLUSCA.

13

Child. It draws its body into its shell for
-protection.
·' Teacher. Yes. The bodies of the mollusca
are contractile, that is, have a stronll'po-iver of contraction, which they exercise by me~ns of muscles.
'\Yhat more do you remark in these· creatures 1
Child. They have a thick skin, which appears
loose in some of them.
Tcachc1·.
This skin is called the sac or mantle ; it is peculiar to the molluscous tribe, and is
constantly moistened by a slimy exudation. It
is also full of pores and glands, of which I shall
have occasion to speak in a future lesson. Can
you explain the nature of pores and glands ?
Child. Pores are very small holes. I do not
·exactly know what glands are ; but we have
glands in our throats, are those of the mollusca
the same as ours ?
Teacher. They are of the same nature, but
much smaller than those in our throats. The
office of glands is to secrete or separate fluids of
various kinds from the general fluid of the substance. All bodies both of the animal and vegetable kingdom are supplied with a great number
of glands; tears in animals are an ·example of
secretions formed by means of such organs, so are
honey and all other peculiar juices of plants. As
the glands form little reservoirs, they oflen appear like small swellings, perceptible to the sight
and touch. To return to the mantle ;, it ·sometimes envelops the mollusca like a purse, leaving
im opening only where the mouth is situated; in
some it extends on the two sides, forming ex2

14

LESSON I.

pansions which perform the part ~f fins. ~om~­
times it spreads over the shell itself, which m
this case has always a fine polish. Remember
I desired you not only to examine the mollusca,
but to compare them with other animals. What
further peculiarity do you discover in them 1
Child. They have no bones, their bodies are
only a mass of soft flesh.
.
Teacher. '],'hey have certamly no bo~es; but
in the mollusca which we purpose studymg, the
shell,' by a.c ting as a support to the body, seems
in some measure to answer the purpose of
bones. What more do any of you discover in
these animals 1
Child. They do not appear to hav.e any blood.
Teacher. They have not red blood as we
have ; but are they composed entirely of solid
matter?
Child. . No, for when a snail is trodden upon,
a white fluid issues from it ; is this its blood 1;
T&aeher. Yes, it may be considered as a ~d
of blood. How does it differ from that wh,ich
circulates through our bodies 1
Child. It is white and cold.
Teacher . . True ; and in consequence some
naturalists have not considered it as blood, .an_d
have. described the mollusca to be exs~gajn­
eous ; a term si~nifying without blood, ~nd
derived from Latin ex, out of, and sanguine,
blood. As this fluid flows through the_ir bodies
in vessels . issuing from their hearts, it is now
generally : called their blood. What are you
watching in the .snail ?

MOLLUSCA.

15

.. Child. The very quick manner m which it
'draws in its horns, and shrinks into its shell, ifit
. is touched.
Teacher. ·what would you determine with
respect to the animal from this circumstance 1
Child. ·.That it has the sense of feeling.
Teacher. Yes; and which part appea;'s most
sensitive 1
Child. The horns. ·
Teacher. And do you observe how the little
animal feels about, and tries with these projections which you call horns ? They .have from
thence been termed Tentacula, from the Latin,
tentare, to try or feel. How many tentacula
have snails 1
Child. Four.
Teacher. The tentacula vary in number ;
many mollusca have only two. The sense of
feeling resides in the nerves.
Child, Oh ! then the mollusca must have
nerves.
Teacher. Yes they have nerves. What other
orwm of sense besides the tentacula do you perceive 1
Child. Thero are black specks on the horns
of the snail which appear like eyes.
. Teacher. These specks arc the organs of
sight, of which the mollusca have never more
than one pair. The sense of seeing, however,
is not universally possessed by this class of animals. The organs of hearing and smelling have
never been discovered among them, but they are
supposed to possess the latter from the readiness

16

LESSON J.

with which they select suitable food. This circumstance also proves that they possess the
sense of taste. You must now recapitulate all
that has been said concerning the mollusca.
Whence is the name derived 1
Child. From mollis, the Latin for soft.
Teacher. What kind of body have they 1
Child. Cold, slimy, soft, and fleshy.
Teachw. Yes ; and another quality you
observed when I touched the snail several
times.
Child. That its body is co_ntractile.
Teacher. And what enabled it so quickly to
contract its body, and retreat into its shelter 1
Child. Its being furni shed with muscles •.
Ttachn-. When you compare these animals
with others, in what respect do they appear
deficient 1
Child. They have no bones, the shell aeting
as a support to their bodies, which are attached
to it by muscles.
.
Teacher. What envelops the mollusca 1·
Child. A sac or mantle.
Teacher. D escribe the mantle.
. Child. The mantle is full of pores and
glands, and is moistened by a slimy ex udationsometimes it quite encloses the animal, having
orily one opening like a purse, sometimes it has
expansions at the side, like fins, and sometiines
it spreads-'over the shell.
Teacher. · What are glands 1
Child. · Small lumps containing fluids, which
are separated from the blood.

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• Ttacher. Yes, in animals the glands contain
fluids secreted from the blood; but in ve"etables
from the sap. Have these animals ~y fluid
answering to our blood 1
r,hild. Yes ; but it is white and cold.
Teacher. In what respects is it similar to
blood 1
Child. It circulates through the body in vessels issuing from the heart.
Ttacher. What senses are enjoyed by the
mollusca 1
. Child• . '!'he senses of feeling, seeing, tasting, and, 1t 1s supposed, smelling.
Teacher. In what part of their frames is the
sense of feeling most acute ?
Child. In the tentacula.
Teacher. Tell me the derivation ofthatterrn?
Child. It is derived from the Latin, Tentare,
to try.
Teache!. But what must they po,ssess in
order to be able to feel ?
Child. Nerves.
Teacher. I will now read to you a summary .
of your lesson, and I shall expect you afterwards
to write it from recollection.
Teacher. The moll~ sca h~ve soft, slimy,
c_old, fleshy, and contractile bodies. They have .
no bones, but their shell ai:;ts as a support to t~eil';
frame. They have muscles by which they are
attached to. their shells, and by which they move
their bodies; They are endose<l in a skin called
the mantle, or sac, which is full of pores and
glands. Sometimes the animal is so completely
2'*

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MOLLUSCA.

LESSON II.

enveloped in this~ as. only to present an opening
where the mouth 1s situated, sometimes it spreads
ornr the shell, and sometimes it has external expansions answering the purpose of fins. The
mollusca have not warm red blood, but a white
cold fluid issues from their hearts and circulates
through their fram~s. · They have nerves, and
consequently, feeling; and this sense seems
most acute in their tentacula. Some have eyes
but others do not enjoy the sense of sight. The;
~ppear to have the power of smelling and tasting, but no traces of ears have been discovered. 'If

LESSON II.
To commv1Ce with a repetition of the summary of
the Janner lesson.) .
·

Tt11€her. E~a~ne these animals again,
compare them w1~h ms~cts, ~nd tell me if you
~bserve any deficiency m their constructio·n.
•This little summ.ary of the substance of the lesson may be read

ov~r l!flCe to the children, and they should then be required. to

write 1t as well ae they can from recollection. It would be well also
tbat they ah(_mld repeat it at the commencement of the succeeding
luson • . This process may appear tedious, but the res ult will be
mo1t.sat1sfactory bott. to the teacher and pupils. The latter should
acquire so clear a ~uow~edge of the facts brought before them, and
ha Ye them so well 1mpn11ted on tlu~ir minds that they may throuah
all their progress, b~ cnab\~d, without co1;fus ion or hes i'ta ti ou t.to
reel.tr to e~b preceding step. Their information should be Jik~ a
chain, whw:b IS hel~ unbrok en in the grasp· and were such the
cue, a power of ·mmd would b~ elicited _whrch, independently or
the ":n.Jue of the ~now ledge ob~amed, wouJd prove its worth when
a.pplied to more important subJeCt9.

Child.

Th~y

19

ha\•e not any limbs.
\'cry true. They have not limbs
or joint!l, n!I insec ts, nor are they divided, or
movccl by means of rings, as worms.
CJaild. Yct they move about.
Ttn<lier. Yes; the greater part of the molhuca ba,·c the power of locomotion; that is, the
power of moving from place to place ; it is derivccl from Latin locus, a place. vVe will first
uamine the organs by means of which it is exrrcised. In what manner do snails and slugs
rn:Ute their way along the ground?
·
Cl1iltl. Their skin seems to expand at the
11ide of the body, and to adhere to the earth, and
then they draw themselves on.
Teacher. This fle shy expansion under their
bodies is full of muscles, which they dilate and
contract at pleasure. It &dheres like a sucker,
and the41nimal advances by fixing the fore part
to the ground and drawing the remainder after
it- This instrument is called a foot. In some
.. i)ecies, as the snail, it is attached to the under
pa.rt of the body by its whole length, but in others
it is free nt one end, and can be e:ttended or
11;thdrawn al ·plcnsurc. When it is free it is
called a leg, nncl is usually tongue-shaped; it is
frequently used as an organ of motion, but som_etimes the animal employs it as a paw for digging
holes in the sand or mud. But consider whether
this organ will enable the mollusca to advance in
all the situations in which they are placed ?
Child. ·No, not when they are in the water ;
then they must swim.
Tu1ch~r.

·~(

EXPLANATION OF THE PLATES.
PLATE I.

Spire.
Body whorl.
Beak.
d. Base.
c. Canal.
I,, Aperture.
Outer lip.
,-, ·
h. Colume llar lip.
'Whorls.
/,
k. Suture.
Apex
in. Back.
n. Varices.
o. Colurnella.
P· Dissepirnents.
q. Umbilicus.
a.
b.
c.

r.
s.

t.
tt.

v.
w.
x.
!J·

z.

a:*
//"
c
d*'

"'

e*

Area or Anterior
slope.
Areola or Posterior
slope
Beaks.
Hinge.
Ligament.
Disk.
Umbo.
Base.
Length.
Breadth.
Auricles.
Left valve.
Right valve.
Valves.

PLATE II.
FIG.

Conus .Nlamwrcus.
Cypnea .llrabica
The same, young.
Cypnea Moneta ,
Cyprrea Ettraprea
Bulla Lignaria
Gizzard of Ditto.
Bulla Volva
• 9. Bulla Fontinalis
10. Voluta Oliva .
11. V oluta Episwpalis
1.
2.
3.
4.
· 5.
6.
'7.
8.

:Marbled Cone.
Nutmeg Cowry.
:Money Cowry.
Nun Cowry.
Wood Dipper.
Weaver's Shuttle.
Stream Dipper.
Olive Volute.
Bishop's Mitre .

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