Elements of zoology; embracing a view of life as manifested in the various gradations of organized beings

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E L E M ENTS

OF

ZOO L 0 G Y.

ELEMENTS

OF

ZOOLOG Y;

EMBRACING

A VIEW OF LIFE AS MANIFESTED IN THE VARIOUS
GRADATIONS OF ORGANIZED BEINGS.

By WILLIAM RHIND,

MEMBER OF THE ROYAL COLLEGE OF SCRGEONS, MEMBER OF THE ROYAL MEDICAL AND
ROYAL PHYSICAL SOCIETIES, AUTHOR OF “ ELEMENTS OF GEOLOGY,” &C.

A NEW AND ENLARGED EDITION.

EDINBURGH:

MACLEOD & SON, NICOLSON STREET.

J. J. CHIDLEY, LONDON.

MDCCCXL V.

PREFACE.

The object of this little work is to afford to students
a concise but connected and systematic view of the vital
functions, and the varieties of animal structure as exem¬
plified in the graduated scale of existence.

As it is intended to serve as a text-book for more
extended lectures, a general view of the classification of
the animal kingdom is also given. In this synopsis, the
arrangement of Cuvier is taken as the basis, with a few
exceptions, which are pointed out in the table at the end.

The illustrative woodcuts are confined chiefly to the
elucidation of organic structure ; an engraved atlas of the
leading orders and genera of animals is proposed to be
afterwards published as a suitable accompaniment.

In using this work as a class book for junior pupils,
certain portions may be at first selected ; as the sections
on the senses and instinct, or a class of animals, as the
mammalia — birds — insects ; while, to the advanced stu¬
dent, a course of more extended reading, as pointed out in
the authors subjoined, may be followed, along with the
perusal of the entire treatise.

IV

PREFACE.

The utility of early training, in the various departments
of natural science, is daily becoming more obvious to the
public generally ; and there is no doubt but that a period
will soon arrive when such studies will be recognized as
regular branches of education in our schools and academies
in this country, as they have long been with the greatest
success in similar establishments on the Continent.

Edinburgh, 21, Forth Street,
April , 1839.

C O N T E N T S.

I’as®

Sect. I. Form and Composition of Organized Bodies, 1

II. Conditions Necessary for Life, . . 4

III. Diversities of Animal Forms, . .* 8

IV. Organs and Functions of Animals, . . 11

V. Nutritive Organs, . . . 13

VI. Reproduction, . . . .25

VII. Organs of Motion, ... 28

VIII. Brain and Nervous System, . . .34

IX. The Organs of Sense, ... 36

X. Temperament, . . . .47

XI. Instinct, ..... 48

XII. Classification of Animals, . . .52

Mammalia, .... 54

XIII. Birds, ..... 73

XIV. Reptiles, .... 84

XV. Fishes, . . ... 88

XVI. Mollusca, .... 94

XVII. Articulata, . . . . .98

Annulata, Worms, ... ib.

Crustacea, Crabs, Lobsters, . . 99

Arachnides, Spiders, . . . 100

Insects, ..... 101

XVIII. Radiata, .... 109

Table of Classification of the Animal Kingdom, 114
List of Works on Zoology, . . .116

Glossary, . . . . 117

Z 0 0 L 0 G Y.

SECTION I.

FORM AND COMPOSITION OF ORGANIZED BODIES.

1. Zoology embraces the history of animated beings, or all
those organized bodies which exhibit the phenomena of sensi¬
tive life.

It includes an account of the structure and uses of the
various parts of the animal machine, points out the difference
of this structure in different tribes, and thus affords the means
for classifying and arranging the numerous gradations which
are found in the vast chain of animal existence.

Zoology also treats of the habits, dispositions, and instincts
of animals, their dispersion over the globe, and the effects
which climate, domestication, and other causes, produce on
them.

2. Although plants are also organized bodies, exhibiting life
in a certain degree, and possessing a property, called irritability,
of being affected by external stimuli, yet they have no real
sensation, and thus differ from animated beings.

3. Organized bodies differ from inorganic or mineral sub¬
stances, in having a structure, more or less complicated, made
up of cells, tubes, and membranes, intimately connected
together, yet performing separate functions or offices, and
obeying different laws from those which prevail in the inorga¬
nic kingdom.

A

ey

ZOOLOG V.

If you take a mineral substance, and break it into minute
parts, every part is complete in itself, and is identical, in every
respect but size, with the body from which it was broken ;
but if you divide an animal thus, every part differs from the
other, and it is only by the junction and combination of nume¬
rous parts and structures that you have a perfect whole.
Mineral bodies are subject to mechanical and chemical laws ;
but, in addition to those, organized bodies are under the con¬
trol of vital laws, which enable them to resist the ordinary
effects of chemical and mechanical actions. It is only when
vital actions cease that organized bodies become subject to
chemical decomposition, and are again resolved into the ele¬
ments out of which they were formed.

4. An animal body is said to be possessed of organs, or to
have an organism. These organs perform certain functions,
which are necessary for the growth and support of the indivi¬
dual — for its locomotion, and for the performance of instinctive
and rational acts.

The performance of these functions constitutes life, — a term
which comprehends the whole manifestations of an animated
being.

For the manifestations of life, then, there is first necessary
an organized body susceptible of vital action, and certain
stimuli to act upon this body, and set it into motion and
activity.

In this view of the subject, organism is made to precede life.

Another theory supposes a “ vital principle,” hn actual though incompre¬
hensible agent, which is the cause of organization, and all the functions,
both vital and sensitive, of the animal machine.

We are told, that in the beginning the Creator first formed the organized
structure, and then “ breathed into it the breath of life ; ” and ever since the
perpetuation of every individual species continues to be accomplished by the
transmission of a portion of this organized matter from parent to offspring.

There can be no doubt, from all experience, but that an organized
structure precedes, or is co-existent with, the manifestations of life ; and yet
we are by no means assured that life is the consequence simply of organiza¬
tion ; that is, that matter, under certain laws called vital, and acted on by
certain material stimuli, produces all the manifestations of life. We know not
whether sensation, or even irritability, be a property of matter simply as
matter, or whether both may not be due to the presence of another principle,
the nature of which is to us incomprehensible.

At the same time, those who assume the agency of a vital principle, do so
on theoretical grounds alone. It is an hypothesis, in its general acceptation,
inconsistent with the fact already noticed, that all experience shews organized
matter as essential to the manifestation of life.

Nothing can be more illogical, however, than the reasonings of the mate¬
rialists, that life and sensation, and even thought, must necessarily result

ORGANISM.

3

from matter alone in a state of organization ; because, to the known condi¬
tions or qualities of matter, they must add that of vital susceptibility, or
irritability, a property which, for all we know, may not belong to matter at
all, but, on the contrary, may be a property of something superadded to it.

“ If, in order,” says Cuvier, “ to obtain a correct idea of the essence of
life, we consider it in those beings in which its effects are the most simple,
we quickly perceive that it consists in the faculty possessed by certain corpo¬
real combinations, of continuing for a time, and under a determinate form, by
constantly attracting into their composition a part of surrounding substances,
and rendering to the elements portions of their own. Life, then, is a vortex
more or less rapid, more or less complicated, the direction of which is
invariable, and which always carries along with it molecules of similar kinds,
into which individual particles are continually entering, and from which
they are continually departing, so tliat the form of a living body is more
essential to it than its matter .”

5. Organized bodies are formed out of a few of the sub¬
stances of inorganic matter.

Carbon, oxygen, hydrogen, and nitrogen, are the elements
of the greater part of the animal and vegetable structure.
Animal bodies are distinguished from vegetable by containing
a much larger quantity of nitrogen ; and hence the peculiar
ammoniacal odour which animal substances exhale when
burned, or otherwise decomposed. In addition to the above,
the following substances also enter into the animal structure :
sulphur, phosphorus, soda, potassa, lime, iron.

Combinations of these simple substances produce gelatin,
albumen, fibrin, mucus, serum, oil, fat, and phosphate of lime,
of which the solid and fluid parts of the body are composed.

C. These substances, however, are only recognized out of
the body, or when the living action has ceased. We know
not under what condition they exist while obeying vital laws.
When death takes place, coagulition, fermentation, putrefac¬
tion, and all the train of chemical actions, soon reduce the
mass to the dust out of which it was originally formed.

• The minute particles of the matter of which organized
beings are composed, as seen by the microscope, exhibit a
globular appearance. Both animal and vegetable fluids, when
thus examined, present an aqueous liquid, with exceedingly
minute globules floating in it. These globules also compose
the solid textures.

8. A general idea of organized structures may be obtained
by conceiving an exceedingly thin texture, forming a congeries
of vesicles or cells, and these cells again joining to form hollow
tubes, either straight, spiral, or branched into minute ramifi¬
cations.

4

ZOOLOGY.

The simplest structure is that of vegetables, where innu¬
merable minute cells and tubes traverse the whole substance
of the plant, and render it porous and permeable to tbe air and
juices which circulate through it in all directions.

No. 1.

a Cross section of a piece of wood, shewing its tubular and porous nature.
b Longitudinal view of detached vessels, c Cellular texture of animal.
d Hollow ramifying branches of veins and arteries.

9. The animal structure is more complicated. A minute
tissue, composed of extremely thin laminte or plates, intimately
connected together, and variously crossed and connected by
fibres, forms a cellular net-work, which is the foundation of
the whole animal fabric. This tissue is highly elastic, and in
its simplest state porous like a sponge, but when condensed
and thickened, it does not permit fluids to pass through it.

This thickened membrane forms the hollow tubes which
branch out into innumerable ramifications throughout the
animal frame, and through which the fluids circulate. It
also lines the hollow cavities of the bodv, and forms sacks
or pouches of various kinds.

Another variety of membrane composes the muscular fibre.
The nervous substance is formed of a soft greyish matter,
and of white fibrous threads.

SECTION II.

CONDITIONS NECESSARY FOR LIFE.

10. Organized bodies susceptible of vitality do not exhibit
tbe usual manifestations of life, unless under certain conditions.
These necessary conditions have been called stimuli. The
direct stimuli are, moisture, air, and alimentary matter or
food, all of which enter into the composition of organized
bodies; and to these are added, heat, light, and electricity.

STIMULI OF LIFE. 5

A seed of a plant, a grain of common wheat, for instance,
contains an organized germ, which remains apparently dead
and inactive as long as it is kept in a perfectly dry state ; but
whenever this grain is put into the ground, and the necessary
stimuli of moisture, heat, and air, are applied, it immediately
springs into life, shooting up a leaflet to the surface, and
spreading its roots into the ground.

Many of the smaller animals illustrate the same circum¬
stances. A minute worm found in diseased ears of corn may
be dried and completely deprived of its juices, and in this state
it will remain for months and years without shewing any signs
of life ; but as soon as a drop of water is put upon it, life and
activity again return. Animalcules may also be thus dried and
revived at pleasure. A cheese mite will remain glued to a
piece of glass, without motion or any of the manifestations of
life, for many months ; but upon being placed on a piece of
xoist cheese, it will instantly revive. Eels and other fishes may
oe frozen into a solid mass by cold, and yet return to life when
thawed.

11. A certain degree of fluidity, then, is a necessary con¬
dition of life. As all organized bodies are made up of cells, and
tubes, and vessels, a free circulation of the various juices
throughout this structure is necessary, both for the manifes¬
tation of living action, and for contributing to the growth and
sustenance of a frame continually liable to waste and decay.
Some animals have much more fluid in proportion to the solid-;
of their bodies than others. The medusie, and many of the
lower tribes, have bodies composed of a thin, watery jelly,
with only a few granular solid particles dispersed in the mass.

12. Air is essential to the life of all organized beings. The
oxygen of the atmosphere is absorbed by all animals by means
varying in different classes. It is directly incorporated into
their blood and nutritive juices, and seems of such importance
to the support of life, that in a great proportion of animals,
its deprivation for even a few seconds proves fatal to exis¬
tence.

Air acts as a stimulus on the whole surface of the skin, but
especially on the lungs, exciting them to activity, and producing
respiration.

13. Food and liquids taken into the stomach act in the first
place as stimulants to the system, and, after digestion and
assimilation, are converted into the organized texture of its
different parts. A supply of aliment is necessary for the growth

ZOOLOGY.

6

and repair of the animal body ; but that food acts in the first
instance as a stimulant, is proved by the immediate refreshing
effect which nourishment taken into the stomach, as a little
soup or a glass of wine, has on the exhausted frame, before
time could have been afforded for its digestion or conversion
into a nutritious fluid. At the same time, it must be obseived
that, during the digestive process, and as long as the nutritious
fluid circulates through the body, its stimulating properties
continue. Although a supply of alimentary matter is necessary
to all animals, and its daily stimulus is, for the most part,
essential, yet in some, its use may be interrupted for days,
weeks, and even months, with perfect impunity. The land
tortoise will live for three or four months without food. Some
serpents fast for several weeks. Insects in the successive
stages of their metamorphoses, and hybernating animals, have
long fasts of several months, in which they are entirely deprived
of all sustenance.

14. A certain degree of heat is necessary for the manifesta¬
tion of life. Neither plants nor animals can exist in a tempera¬
ture which is permanently much above or much below 50°, or
the temperate heat of Fahrenheit’s thermometer. Cold-blooded
animals, such as fishes, reptiles, and the mollusca, possess a
temperature very little elevated above the water in which they
live, nor have they the power of resisting a cold much below
that of freezing, without having their vital faculties suspended.
Hot-blooded animals have a temperature varying from 90° to
110°. These have a power of resisting or modifying both
extremes of heat and cold ; yet if intense cold be long con¬
tinued, the vital functions at length give way.

A medium degree of heat, then, is a necessary condition of
existence, while extremes of heat or cold are fatal to life. The
young of animals can bear the extremes of heat and cold less
than the full grown ; while it is remarkable that the spawn or
eggs of many of the inferior animals can be subjected to
extremes of both with greater impunity than the parent
animals.

All animals in a certain degree, but especially the higher
classes of the vertebrata, have the power, by means of their
respiratory functions, of producing heat within their bodies, so
that they can maintain a temperature much above that of the
surrounding air. Thus a hare or a field-mouse keeps up a
temperature, in the freezing months of winter, at least 50° or
00° above that of the earth or snow among which it burrows.

STIMULI OF LIFE.

.

It must be remarked, also, that the temporary application of
cold acts as a powerful stimulant on the body, exciting the
vessels of the skin to an increased action. After a time, how¬
ever, this stimulus exhausts the powers of life, and the con¬
tinued effects of extreme cold is to diminish the vital actions,
induce stupor or sleep, and finally death.

15. Light also appears to be a necessary stimulus of healthy
vitality. In plants, the influence of light is very apparent.
Those that vegetate in the dark are sickly, and totally devoid
of colour : their natural juices are not secreted, of the usual
flavour, nor do such plants ever come to full maturity. Animals
seem no less generally affected by light. To its influence they
owe their colour, the full exercise of vision, and perhaps in a
considerable degree the robust vigour of their bodies.

Fishes confined in a dark vase have been known to lose their
variegated hues. Intestinal animals are almost entirely devoid
of colour; and probably the pallid countenances of the inha¬
bitants of the dark lanes and manufactories of cities are as
much owing to their deprivation of light, as of the pure air and
healthful exercise of the open country.

16. Electricity is an agent so universally dilfused over all
terrestrial bodies, and is found so uniformly present in all
organized beings, as to lead us to presume that its influence as
a stimulant to the animal frame must be considerable.

The electric changes in the atmosphere evidently affect all
animals, from the lowest to the highest. Thus the sea anemonv
( actinia ) is so sensible of atmospheric changes, contracting its
tentacula more and more on the approach of storms, as to be
looked on as a faithful marine barometer. The common leech
is also greatly agitated before thunder or rain ; so are wild¬
fowl and many quadrupeds. And man, too, feels his spirits
depressed, and his frame unusually affected, during certain
electric states of the atmosphere. Artificial electricity is also
one of the most powerful stimulants of the animal system.

Although the external influence of electricity seems to be
considerable on the animal frame, we are as yet ignorant
whether it exercises any other more special agency.

The accumulation of electricity by some fishes, as the gym-
notus, as a means of defence against enemies, has no connection
with this fluid as a general stimulant.

8

ZOOLOGY.

r

SECTION III

DIVERSITIES OF ANIMAL FORMS

17. The diversities of animal structure are very numerous,
from the simplest condition of organized existence, up to the
most complicated. It requires, indeed, but a very few parts
simply to manifest life as we find it in the very lowest animals.
A thin membrane, formed into a hollow bag, and containing
a single cavity or stomach, which receives the alimentary
fluid by imbibition or absorption, is one of the simplest struc¬
tures manifesting life, as seen in the hydatid.

If to this we add a mouth and elastic gullet, for receiving
and conducting the food into the stomach, we have another
animal of very similar structure and habits, the cysticercus,
found inhabiting the cellular tissues of other larger animals ;
and the hydra or water polype, consisting of a cylindrical,
gelatinous body, which is also a hollow stomach, a mouth and
tentacula, or elastic arms surrounding it, for the purpose ot
grasping the insects and worms on which it preys.

No. 2

b

d

a

c

a Simple hydatid — b Cysticercus celluljsa — c Lemna gibba — d Hydra viridis.

As we advance in the order of being, we find superadded to
this single organ of a stomach, a nervous system of ganglions
and brain, a circulating system of heart and bloodvessels,
a respiratory system of gills, or lungs, or branchiae, and a mus¬
cular system, with a firm shelly or horny external covering,
or a regular skeleton of bones, for all the purposes of extensive
locomotion.

18. With all this diversity of structure, there is a general
uniformity of plan which pervades the whole system of orga¬
nized existence. This is remarkably evident throughout the
several divisions of the animal kingdom ; but even in the
arrangements of the animal and vegetable systems, there are
such remarkable coincidences, as lead us at once to conclude,
that both have been constructed on one common principle.

DIVERSITY OF FORM.

9

Thus, if we compare the simplest plants and simplest
animals together, we shall find a striking similarity in their
structures, as well as a uniformity in their functions.

The common duck weed, fig. 2. c. found in abundance in
ditches and pools of water, has a green seed-like body, of a
cellular structure within, with numerous roots, which, floating
in the water, absorb the necessary juices through their hollow
tubes, and convey this food to the body of the plant, where,
as in the leaves of more complicated vegetables, it is mixed
with a portion of atmospheric air, and is thus rendered a
nutritious fluid for the nourishment of the plant.

b is the cvsticercus already described, with a body somewhat
similarly shaped as the lemna ; instead of roots, it has one
tube, the esophagus, opening by a mouth through which it
absorbs the fluid in which it floats, and converts it by a process
of assimilation into its proper nourishment.

Even in the more complicated classes of vegetables and
animals, though the means are different, the plan is still
similar.

Thus, the higher animals and plants resemble each other in
having the following organs performing similar functions.

In a Plant.

The root,

vessels of the stem,

leaves,

ovary.

In an Animal.

The stomach,
arteries and veins,
lungs,

, uterus.

19. In the animal kingdom, the multiplicity of species, and
the myriads of existing beings, are no less objects of our asto¬
nishment.

Of vertebrated animals, at least 12,000 distinct species
have been recognized. Of mollusca not less than 6000. Of
articulated animals upwards of 100,000. Of zoophytes and
infusory animals, several thousands have been enumerated.

To this list we may probably add at least one-third
more of the inferior species yet unknown or undescribed.
When we consider that many of these tribes are most prolific,
some species producing a million in one season, the actual
amount of animal life existing at one time on the face of the
earth must be immense. We cannot turn our eyes to any
part of nature that is not teeming with life : the earth, the
ocean, and the air, swarm with their respective myriads ; and

ZOOLOGY.

10

if we call to the aid of our limited vision, the powers of the
microscope, we shall find every drop of fluid a little world,
swarming with inhabitants, all active and busy, and apparently
full of enjoyment. Even the bodies of the larger animals
want not their respective parasites, both without and within,
and thus being is heaped and crowded upon being.

20. Although we thus find an infinite diversity of kinds, each
differing from the other, some widely, and others by almost
imperceptible shades, yet nature, when not interfered with by
man, preserves among all these the most rigid distinctions, so
that we find no blending or confusion of species. Had it been
otherwise, there would have been no end to the divergence
and monstrosities of forms.

There are also many wise provisions and adjustments for
the preservation of the different races. Thus animals of prey
produce much fewer young than those that are liable to be
preyed upon. The eagle and the hawk bring forth only two
or three young in a season, whereas the rabbit, the partridge, and
the smaller birds, are very prolific. The species of carnivorous
quadrupeds, as the lion and tiger, are few and thinly scattered,
while those of the graminivorous races are numerous and
abundant.

Graminivorous animals produce their young early in spring,
in order that they may have a supply of green and tender herbs ;
and the same appropriate period of production with regard to
food takes place with all other animals. The stated propor¬
tions of males and females, too, is regulated by a nice and
invariable adjustment ; for there is never found, either
among animals or man, an undue excess or deficiency of
either sex.

21. The animal kingdom has been compared to a great chain,
portioned out into several leading divisions, and these again
made up of many links. Now, although there is not found
that continuous and uninterrupted passing of one link into the
other, which has been thus imagined ; but, on the contrary,
there appears in many cases considerable blanks, and according
to some theories, as if the great chain of being was composed
of circular groups, returning into each other again and again ;
yet even amid all the apparent diversity, the leading principle
of all the various organs, and their functions, is preserved
throughout. Thus, amid infinite diversity of apparatus, the
digestive, the respiratory, the circulating, and absorbent func¬
tions, all lead to the same results throughout the whole ; and

DIVERSITY OF FORM. 1 1

the muscular and nervous systems, though progressive, are all
strictly upon one uniform plan.

If we examine the details of structure more minutely, we
shall find these resemblances in many instances very striking.
In vertebrated animals, or those possessing a regular skeleton,
comprehending fish, reptiles, birds, quadrupeds, &c. there
is great diversity of external appearance, and yet a singular
uniformity of the bones composing the skeleton prevails.
Thus, in all this great division, we have the distinguishing
characteristic of a vertebral column forming the spine.

To this column, in its simplest state, as in serpents, we
have gradually added the upper and lower limbs. The fins
of fishes becoming the wings and legs of birds ; the wings of birds
passing into the fore legs of animals ; and these again into the
hands of man. Then, if we go more into detail, we find that
the paddles of the whale have nearly the same number of bones,
with a similar form to those of the human hand. The fore
paws of the mole are exceedingly like the hands of man — in
the turtle there is a near resemblance to the human thumb.
There are the same number of bones in the neck of the
camelopard, the seal, and in man, and the fore paws of the
seal, the claws of the bat, and the human hand, though formed
for different uses and different elements, are in structure
nearly alike. The orbit of the eye, too, in all the classes of
the vertebrata, is formed by a junction of the same seven bones
of the head and face, which are common to the whole.
Viewed externally, the turtle and the tortoise would appear
animals totally different from the other vertebrata, but inter¬
nally they possess a true skeleton, to which the outward shell
is superadded.

SECTION IV.

ORGANS AND t UNCTIONS OF ANIMALS.

22. Viewing the animal body as a machine, it may be
justly pronounced as infinitely superior to the most elaborate
contrivances of human invention. It has not only a most per¬
fect mechanism, but, unlike all human machinery, it generates
its own power, supplies its own waste, repairs its damaged
structure, generates its own heat, enlarges its dimensions, and

ZOOLOGY.

12

moreover produces from its substance other new forms of a
similar structure with itself.

The various functions of the animal body may be classified
thus : — •

Nutritive,

Reproductive,

Sensitive or
Relative.

Functions.

' Digestion and assi¬
milation.
Respiration.

Circulation.

Absorption.

1

{

Generation.

j Voluntary motion.

Sensation.

I Instinct
l Reason.

Organs.

( Stomach, liver, Ac. — intestines—
( lacteal vessels — glands.

Spiracles —gills — lungs.

( Dorsal vessel — single and double
( heart — arteries — veins.
Absorbent vessels and glands.

{From any part of the trunk of the
body in gemmiparous animals.
Ovaries — uterus.

( Muscles — tendons — bones— horny
( and crustaceous sheaths.

^►Nerves— ganglions— brain.

*23. For performing these functions, various organs are
required. In the lowest scale of animals, the organs are
extremely simple, and the vital functions performed are few.
As we ascend in the scale, other organs are successively added,
till at last we arrive at the top of the scale, where they are all
present.

This diversity of structure affords the most scientific means
of arranging and classifying animals, and is the basis of all
modern zoological systems.

Thus, in the four great divisions of the animal kingdom, the
arrangement proceeds, from the simplest structure up to the
most complex, in the following manner : —

Zoopiiyta.

Insecta.

Mollusca.

Verteerata,

{

{

{

<

Stomach, or cavity in gelatinous pulp —
mouth — tentacula — skin — two senses.

Stomach— mouth, Ac. — dorsal vessel —
spiracles — brain — ganglions — skin —
muscles — external horny and shelly
covering— three or four senses.

Stomach — heart — blood-vessels — brain —
nerves— lungs — muscles — skin — shelly
covering— two to three senses.

Stomach — mouth— teeth, Ac. — heart —
arteries — veins — lungs — gills — brain,
and complete nervous system — internal
bony skeleton — external covering of
hair, wool, feathers, Ac. — the five
senses.

} Irritability —
sensation.

} Instinct well
developed.

>

Instinct mode¬
rately deve¬
loped.

Instinct highly
developed — pas-
y sions — sympa¬
thies — in man
, reason.

NUTRITION.

13

SECTION V.

NUTRITIVE ORGANS.

24. The Stomach. — We have seen that the stomach
is the first and only organ which is perfectly developed in the
simplest class of animals. This was a necessary provision, as
the growth and repair of the body depend on the digestion and
assimilation of food taken into this organ. A stomach, then,
of some kind or other, may be said to be common to all
animals. It is true, in the very lowest class there are scarcely
indications even of this organ ; some of the gelatinous forms
supposed to possess animal vitality exhibiting only a porous
mass, where the nutritious fluids are probably imbibed as into
a sponge.

The hydatid, the hydra, ana all animals above this class,
however, possess proper stomachs.

The stomach is generally a simple sack, of a round or
oblong shape, with an opening at both ends, one attached to
the gullet, or esophageal end, the other called the pgloric ,
forming the commencement of the intestines. The outer
covering of the stomach is a muscular membrane, the inner is
called the villous coat. This latter is studded with numerous
villi or vessels, having the appearance of a piece of velvet ; it
is of a pink colour ; and from the mouths of these vessels is
poured out the gastric juice, the chief agent in digestion.

25. The gastric juice is a clear, odourless, and almost taste¬
less fluid, which is constantly secreted in the vessels of the
stomach, and which is retained in these vessels till the food is
swallowed.

After the food has been prepared by mastication in the
mouth, or by other means has been reduced to a soft pulp, it
is forced by the muscular contraction of the gullet into the
stomach. A certain quantity of fluid is generally taken into
the stomach along with the more solid food, the greater part
of this is almost directly absorbed by the blood-vessels, and as
much only is left as forms the aliment into a thin pulp. The
gastric vessels being now stimulated by the contact of the
food, pour out their fluid upon the mass, which is gradually
dissolved. To aid this process, the muscular coats of the
stomach successively ;ontract, and thus turn over and over
the mass till every particle of it has come into contact with the

ZOOLOGY.

14

dissolving fluid. A greyish paste is now produced called
chyme. The action of the gastric juice is strictly chemical.
It completely changes the nature of the food ; and whether
this has been animal or vegetable, or a mixture of both, the
properties of the chyme are nearly, if not altogether, the same.
The gastric juice varies in different animals. In those which
feed on vegetable matter, it dissolves these substances only,
whereas grain and vegetables pass through the stomach of a
carnivorous animal, without undergoing any change.

The gastric juice, in the healthy state of the stomach, pre¬
vents fermentation, and corrects any putridity of the food. It
has this singular property, too, that although it readily dissolves
dead animal matters, and reduces them in a short time into a
thin pulp, it will not act on the living fibre, as the coats of the
stomach itself.

The chyme now passes out of the stomach by the pyloric
orifice. Around this orifice, however, there is a valve, which
immediately closes when any portion of undigested food
attempts to pass the barrier, and a contraction of the lower
part of the stomach throws back this portion to the place of
digestion, while the digested chyme gains at all times a ready
exit. The chyme, after having been mixed with the bile and
the pancreatic juice, which are both poured into it from their
respective ducts, that enter into the duodenum, or upper part
of the intestine, then becomes chyle , a white cream-looking
fluid, which, being collected by numerous lacteal vessels,
opening with minute mouths on the inner coat of the intes¬
tines, is at last poured by one large duct into the circulating
system. (32.)

2G. In carnivorous animals, the stomach is a simple bag of
moderate proportional size, the intestines being simple, and of
moderate length.

In graminivorous animals, the stomach is large, or there are
four stomachs, some of which are formed into numerous cells
or folds, and the intestines are also long and complicated.

In granivorous birds, there is a crop or preparatory stomach
and gizzard. In omnivorous animals, the stomach and intes¬
tines are of a medium size.

The reason of these arrangements is, that animal food is of
easier and quicker digestion than vegetable : the latter requir¬
ing nearly double the time to pass through the different
stages of digestion before it is converted into chyle. An
animal diet affords the greatest concentration of muscular

NUTRITION. 15

power. Vegetable food is reckoned lighter and less stimu¬
lating.

27. The mouth and teeth are intimately connected with
digestion. A great proportion of the vertebrated animals are
furnished with teeth, and these are particularly indicative of
the classes to which the individuals belong. Carnivorous
animals have long, sharp, pointed teeth ; graminivorous
animals flat round ones.

There are four forms of teeth genet ally met with : the
incisors, situated in front of the jaw ; the canine or dog teeth on
each side ; the bicuspidati and the molares towards the back.

No. 3.

a incisors — b cuspidati or canine — c bicuspidati — d molares.

As the teeth form important characteristics of many species of animals,
their relative numbers and positions in both jaws are designated thus :

Incisors, . . . -J-

Canine, ....

Molar, • • • S

The upper and lower numbers indicating the upper and lower jaw.

In the mouth are situated the salivary glands, that secrete
the saliva or fluid which assists in mastication.

Birds are destitute of teeth, but have a hard, horny bill
instead. Insects have palpi or horny lips. Some crnstaceous
animals, as the crab and lobster, have teeth at the entrance of
their stomachs.

28. The sensation of hunger is an uneasy feeling, arising either
from the stimulating effects of the gastric juice on the nerves
of the stomach, or from an unexcited condition of the same
nerves, arising from the want of the natural stimulus of food
or chyme. Surprise, grief, and other affections of the mind,
interrupt digestion, and allay the feeling of hunger from their
effects on the nervous system.

Thirst is generally caused by a deficiency of fluid in the
stomach or blood-vessels, or from salt or other stimulants taken

ZOOLOGY.

16

into the stomach ; yet it does not always arise from this, but
rather from some condition of the nerves of the throat or
stomach. A little tea, or a spoonful of acidulated fluid, or
simply chewing a piece of wood, or other hard substance, and
promoting a flow of saliva, will often relieve thirst, when
large draughts of water will fail to do so.

No. 4,

S the stomach, a little displaced
from its natural position, e the eso¬
phagus. L the liver, divided into the
right and left lobes, Lr, LI. g the
gall bladder, its duct seen joining the
hepatic duct, and both entering by a
common duct, into the upper part of the
Intestines, p the pancreas, with its
duct, near the bile vessels, s the spleen.
CC the colon, or large intestine, kk
the kidneys, with the ureters, t/ u,
passing to the bladder, b. a is the
aorta. In this diagram the ileum or
small intestines are removed.

29. The Liver, the purpose of which is to secrete bile, is an
important organ in the process of assimilation. This organ, or
some equivalent, is found in the greater proportion of animated
beings ; indeed, throughout the whole, with the exception of
the very simplest. The biliary organs are also generally large
in proportion to the other viscera. In man and the mammalia,
the liver occupies the right side of the body, fig. 4. It is
divided into two lobes, the left overlapping the stomach. It
is of a convex form above, and concave below; of considerable
thickness behind, and then passing gradually into a thin edge
in front. The colour is dark brown.

A large vein, the Vena porta , collecting the blood from the
intestines, enters the liver, and there spreads out into numerous
branches. It is also supplied with arterial blood by the hepat'c
artery. The minute branches of the portal vein form, through¬
out the substance of the liver, numerous lobules or little net¬
works, along with the minute branches of the artery and vein.

NUTRITION. 1 7

From these the bile is secreted, which is afterwards collected
into the gall-bladder and ducts.

On the under edge of the right lobe is situated the gall¬
bladder, a duct from which passes onward to join another from
the liver, while this common duct terminates in the duodenum,
or upper part of the intestinal canal, immediately behind the
pyloric extremity of the stomach. Bile is a greenish-coloured
bitter fluid, having alkaline qualities, and containing resin and
carbon. Its admixture with the newly-formed chyme converts
this fluid into chyle.

30. The Pancreas , or sweetbread, lies behind the stomach.
This gland secretes a fluid like the saliva, and pours it into the
duodenum by a duct which enters near the common bile duct.

31. The spleen is a gland on the left of, and behind the
stomach, the use of which in the animal economy is not suffi¬
ciently ascertained.

32. The lacteal vessels arise from the inner coat of the
intestines, by very minute mouths, and in great numbers.
They join together into knots or glands ; larger vessels pro¬
ceed from them, and these again unite into one trunk of con¬
siderable size, called the thoracic duct, which, passing up by
the side of the aorta, at last joins the left subclavian vein, under
the left arm.

No. 5.

t i a portion of the ileum. 1 1
lymphatic vessels, d d thoracic
duct, v left subclavian vein, e, e,
absorbents, a the aorta.

The use of these lacteal vessels
is to take up the chyle as it is
propelled forwards through the
intestines, by a successive con¬
traction of their muscular coats.
The greater part of the chyle is
thus taken up in the ileum or small
intestines ; those portions of the
food which are unfit for nourish¬
ment, and the remainder of the
bile and other fluids not required
in assimilation, being carried out
of the system by means of the
larger intestines.

The chyle or nutritious fluid,
having been poured into the blood
by the thoracic duct, has to pass
through the lungs to be aerated
B

ZOOLOGY.

18

or combined with oxygen, when it becomes true blood, and
is circulated to every part of the body, giving off new particles
to each of its tissues and fabrics, — thus depositing bone,
muscle, cartilage, hair, nails, or nervous matter, where it is
required. It is thus that additional matter is furnished to
the body, whereby it grows and increases ; and thus, when
wounds are inflicted, or part of the flesh cut out, the injuries
are carefully and speedily repaired.

33. The length of the intestines in man is about six times
the length of the body, or thirty to thirty-six feet. In car¬
nivorous animals, they are somewhat less than this proportion ;
while in graminivorous animals, they are at least ten times the
length of their bodies.

34. The superfluous fluids taken into the stomach, and
otherwise absorbed into the blood, together with various salts,
are drained off by means of the Kidneys , (fig. 4, k k ) situated
in the loins, into which two bloodvessels enter, while a small
vessel, the ureter, (u u) passes from each to the bladder for
the conveyance of the urine.

35. Respiration. An admixture of oxygen, and probably
a portion of the nitrogen of the atmosphere, with the animal
fluids, is indispensable to life, as well as a free exit to the
excess of carbonic acid formed in the system. Between this
constant interchange of gases and the animal fluids, as connected
with life, there seems to be somewhat of the same resemblance
as the union of oxygen and carbon in the phenomena of com¬
bustion.

In a great proportion of animals, and especially in the higher
orders, air seems the most indispensable stimulus of existence,
the deprivation of it for a few minutes, or even seconds,
generally proving fatal.

There are various means by which this combination and
interchange take place among animals. By simple absorption
through the porous skin, as in the lowest animals ; by spiracles,
as in insects ; by branchiae and gills, as in fishes and aquatic
mollusca ; by lungs, as in the vertebrata.

In man and the mammalia, the lungs occupy the upper part
of the chest, one half on the right, the other on the left, with
the heart and its great vessels in the middle. They are com¬
posed of innumerable cells, over which minute branches of
bloodvessels spread like a fine net-work. When collapsed,
they are of a dark purple colour ; but when the cells are filled
with air, they become of a lighter hue. Every time an inspi-

CIRCULATION. 1 9

ration is made, the cells are filled with air, when the bulk of
the lungs increases, so that they nearly fill the cavity of the
chest. An expiration empties them, when they again collapse.
The muscles used in breathing are those between the ribs,
called intercostal ; and the diaphragm, a large muscle which
entirely separates the chest from the abdomen, and which
extends from the back bone and ribs to the front of the chest
or sternum.

The trachea, a cartilaginous tube, forms the passage between
the lungs and the throat, and opens into the same cavity as the
gullet, or tube leading to the stomach. To prevent particles
of food or drink from passing down into the lungs, there is a
valve, called epiglottis, which shuts accurately over the trachea
«very time a mouthful of any thing is swallowed.

This cut represents a sec¬
tion of the pharynx, or the
throat immediately behind
the mouth. The gullet or
passage to the stomach lies
behind the trachea, t, and
may be considered as the
direct continuation of the
pharynx and mouth. The
windpipe or tube to the
lungs opens into the throat
as at t. I is the valve or
epiglottis, u is the uvula or
little tongue hanging from
the roof of the palate, im¬
mediately above is the open¬
ing into the no3e.

that it never, except
from some awkward position of the body, neglects its duty.
When any substance does enter the trachea, violent coughing
and spasmodic action of the muscles throw it out again.

36. The circulation in the lower animals is carried on
through the interstices of their cellular structure, or by simple
tubes or vessels ; in the more perfect, by means of a heart and
bloodvessels, the arteries carrying the blood from the heart
through the body, while the veins return this fluid again to the
heart.

The simplest circulation is that performed by a single heart,
or one having only two divisions. Of this kind is the circu-

ZOOLOGY.

20

lation of mollusca and fishes. A hollow cavity, or auricle,
receives the venous blood from the extremities ; from this
cavity it passes into another, the ventricle ; by successive con¬
tractions of this muscular cavity it is sent to the gills, and from
thence it flows by arterial vessels throughout the body, to be
again returned by the veins.

The heart of the mammalia is double, containing a right half
for the reception of venous blood, and for sending this into the
lungs, and a left half for the reception of arterial blood, which
comes purified from the lungs, and is propelled through the
aorta, and its ramifications of arteries, into all parts of the
body.

This diagram will simplify the expla¬
nation of the double circulation. The
right side of the heart, with its accom¬
panying venous vessels, is of a dark
colour ; the left side, containing the
arterial system, is white, a is the vein
carrying the blood into the right auricle,
b. From this cavity it is propelled into
the right ventricle, c ; and from thence,
by the pulmonary vessel, d, it is made
to circulate through the lungs. The
vessels, e , return the purified and now
florid blood from the lungs into the left
auricle, f ; from thence it is sent into
the left ventricle, g ; and from this
cavity it is propelled into the aorta, h,
which circulates it over the whole body ;
and then, by numerous minute vessels,
joining the veins, it returns again to the
heart.

No. 7.

The heart is a thick muscular mass, having two halves
joined together, each half containing two cavities, the right
auricle and right ventricle, the left auricle and left ventricle.
Its position with regard to the lungs is seen in the annexed
cut.

CIRCULATION.

21

No. 8.

i

h

L

E esophagus. L L lungs divided into
lobes, a a ven® cav®. b right auricle.
c right ventricle, d pulmonary arteries,
ramifying in the lungs, e e pulmonary
veins, returning the arterial blood to the
left auricle f. g left ventricle, h aorta,
forming an arch, giving off arteries to
the head and arms, and then descending
to supply the lower extremities h.

The two venae cavae which collect the whole venous blood
of the upper and lower parts of the body, open into the right
auricle. From the right auricle is a passage into the right
ventricle, and from this ventricle arises a large vessel which
carries the venous blood to the lungs. Into the left auricle
vessels open, carrying the arterial bright blood back from
the lungs ; then there is a passage from this auricle into
the left ventricle, and from the ventricle arises the aorta
or great artery of the body, which carries out the arterial
blood. It is by the sudden and strong contraction of the
muscles of the heart, that the blood is thus propelled ; and
it will also be seen, that there are four distinct and separate
contractions of the cavities. Without some suitable contriv¬
ance, the blood during these contractions would flow from one
cavity to another, without any regularity, and regurgitate from
one to the other. But to obviate this, there are valves placed
at the entrance of each of these cavities, of a beautiful structure,
which accurately close over the orifices when the blood
attempts to regurgitate, but which open again to let the proper
current from the cavity pass onwards. These valves are
seen, fig. 7.

37. The circulating process connected with respiration is
this : The venous blood collected from all parts of the body, of
a dark purple colour, and charged with carbonic acid gas, is
received into the right auricle, and is from thence transmitted
into the right ventricle. The right ventricle now contracts
and discharges its contents into the pulmonary artery, which

ZOOLOGY.

22

goes to the lungs, the valve in the opening between the
ventricle and auricle shutting, and preventing the blood from
flowing back into the auricle. The venous blood, on arriving
in the lungs, is spread over the surface of the numerous cells
by means of the minute branches of the arteries, an inspiration
of air into the lungs takes place through the thin membrane
of the cells, the carbonic acid in the venous blood is thrown
off, and an equivalent quantity of oxygen is absorbed. The
blood immediately changes from a dark purple to a bright
scarlet, and the air expired from the lungs is now found to
have lost a portion of oxygen, and to have obtained the
same proportion of carbonic acid gas. The oxygenized blood
now returns to the left auricle of the heart ; from this a sudden
contraction forces it into the left ventricle ; and a contraction
of the left ventricle, the passage to the auricle being closed
by a valve, sends it into the aorta in a flowing stream, from
whence, partly by the original impulse of the heart, but chiefly
by a contractile power of the muscular coats of the arteries, it
flows in regular pulsations through innumerable ramifications
to every part of the body. The minute branches of the
arteries either join into, or meet in some way, the equally
minute branches of the veins ; and these latter, in a slower
current, and with no perceptible pulsations, carry back the
now darkened and carbonated stream to the left auricle of the
heart, from whence, after aeration in the lungs, it flows out
again in never-ceasing courses from the heart.

The veins are of larger capacity than the arteries, but less
muscular in their coats. Those veins near the surface, and
especially in the extremities, are furnished with numerous
valves, to prevent the regurgitation of the blood. In the
arteries it will be perceived, from the foregoing description,
that the blood flows from the heart outwards to the extremi¬
ties ; in the veins the blood flows from the extremities to the
heart.

38. The frequency of the heart’s pulsations differs in diffe¬
rent animals, and in individuals according to age. In large
animals, the circulation is usually slower than in small ; young
animals have a quicker circulation than old.

The pulsation of a child varies from 100 to 120 beats in a
minute ; that of a grown up man from 65 to 75 beats.

So perfect and durable is the muscular powers of the heart,
that it unceasingly pulsates throughout a long life, from the
first moment of birth to the last pang of death. This regular

CIRCULATION.

2n

action, too, is happily made independent of the will, or of any
of those accidents or interruptions to which, under human
guidance, it would invariably be subject.

39. The respiratory and circulating functions are also the
source of animal heat. It has already been stated, that all
animals generate and maintain a temperature higher than that
of the surrounding media. This is particularly the case in
those animals with complete respiratory organs.

The cause of animal heat seems to be as follows : — The
oxygen absorbed by the blood in the lungs in passing through
the arterial vessels combines with carbon to form carbonic
acid, and during this combination, gives out a portion of its
latent caloric. This increase of heat does not appear to be
made at once in the lungs, but the caloric seems to be gra¬
dually evolved throughout the whole extent of the circulating
system.

Every inspiration we make, then, and while we interchange
a quantity of carbonic acid for oxygen, we take in a portion
of latent coloric, which is gradually evolved as the arterial
blood passes into venous.

The more perfect and frequent the respiratory functions,
therefore, the greater the accumulation of animal heat. And
thus the want of due exercise, by lessening the respiratory
efforts, the slower respiration in sleep, and the debilitating
effects of disease, all tend to diminish the natural heat of the
body.

A healthy person makes, on an average, twenty inspirations
in a minute. The quantity of oxygen consumed in the same
space amounts to about thirty-one cubic inches.

40. The Blood, or great nourishing fluid of the body, con¬
sists of serum, a thin watery substance like whey, and coagulum,
or gelatinous matter, containing minute red particles of a
spherical form. While circulating in the living body, it is
perfectly fluid ; but, when exposed to the air, and removed
from the bloodvessels, it quickly coagulates, and separates
into the three parts just mentioned.

In blood is contained all the ingredients which enter into
the composition of animal bodies. In several classes of animals,
the colouring matter of the blood is wanting ; hence the divi¬
sion into white and red blooded. In very minute blood¬
vessels, as those of the eye, the colourless part of the blood
alone circulates. When inflammation enlarges those vessels,
however, they admit red particles.

ZOOLOGY.

24

41. Secretion and Deposition is effected, either directly
from the mouths of arteries, or from glands. Glands are
formed of a congeries of minute arteries, veins, and nerves,
rolled up, as it were, together, and intimately connected with
each other. Here the particular substance is secreted, and a
duct leads from the gland to convey the secretion to where it
is required. Of this nature are the glands of the liver, pan¬
creas, kidneys, &c.

42. The Absorbent system consists of a series of minute
tubes, which traverse the whole body, and are found entering
into every cavity, and pervading every membrane and tissue.
The branches of these minute tubes often join, and form small
glands, which, when diseased or obstructed, are felt like small
peas under the skin. Innumerable small branches of the
absorbents open under the skin, and into the cavities of the
body, while the deeper seated combine to form larger trunks,
which join the thoracic duct and bloodvessels. fSee fig.
5, e e .)

The absorbent system may be said to be in direct opposition
to the assimilative. The office of these numerous and minute
vessels is to take up both the solids and fluids of the body, by
what is called absorption, and ro throw them off by exhala¬
tion and perspiration, or to return a portion of them into the
bloodvessels, to be again incorporated into the system. The
waste produced by the incessant action of these vessels is so
considerable, that a human body loses two or three pounds in
the course of a day.

Thus, during disease, a muscular ana fat person will, in
two or three weeks, be reduced to almost a third of his former
weight by absorption. Hibernating animals, that pass several
months of winter in a state of torpidity, without feeding, are
also thus reduced from a condition of plumpness to mere
skeletons. This is the case with some species of polar bears :
with the hedge-hog, the badger, and others.

43. Not only are the fluids and soft parts of the body thus
absorbed, but even the bones, tendons, and toughest membranes
are gradually broken down, and taken up particle bv particle,
so that the entire substance of the animal frame is changed
and renewed many times in the course of a lifetime.

The growth of hair, nails, claws, and horns, and the repeated
abrasions and renewals of the external skin, are familiar
examples of this change; and with the exception of the teeth,
which, after one renewal, remain permanent, there is no other

REPRODUCTION.

fabric of the body which is not constantly undergoing progres¬
sive decay and restoration.

44. The absorbents not only exhale vapour from the
body, but also take in a quantity of watery fluid when the
state of the system requires it. This fluid, along with the
absorbed juices of the body, is poured into the circulation
in the form of lymph. A modification of action also takes
place between the absorbent, the exhalent, and the urinary
vessels, by which a regular balance of the fluids of the body is
produced.

When the digestive and assimilating functions give way,
while the absorbents still continue in activity, gradual dissolu
tion ensues, and thus life may be said to be extinguished by
the activity of the absorbing system becoming greater than
that of the conservative. The flame of existence goes out for
want of a supply of the material of combustion.

45. From this excess of action of the absorbents arises
the tendency of all parts of the body after a time to become
hard, stiff, and solidified ; and thus gradual decay may be
so far accounted for.

We are totally ignorant, however, of the peculiar law of
vitality, which limits the duration of life, either in the species
generally, or in the individual. An animal in the prime of
life, and in full health, appears to be possessed of the properties
of an indefinite existence. It is true, a continued waste is
going on in its system, but it has also, to all appearance, within
itself the means of constant renovation.

SECTION VI.

REPRODUCTION.

46. Organized beings not only increase their own growth,
and repair the continual waste of their substance, but they
also produce other beings similar to themselves ; and thus a
continued chain of offspring succeeds from the first of each
created species to the last.

In many plants, a slip or portion of the organized substance
of the parent plant put into the ground, immediately begins to
assume an independent life. Roots shoot out and absorb
moisture from the soil, while new buds and leaves spring from
the stem.

ZOOLOGY.

26

In other cases, a seed is formed from the plant which con¬
tains the organic germ of the future vegetable. It seems to be
a universal law throughout all organized beings, that every
species propagates its own peculiar kind, and no other, —
equivocal generation, or an animal of one species springing
from an animal of a different species, having no confirmation
in facts, although theories of this kind are not without sup¬
porters. Spontaneous generation, or the idea that plants and
animals could be produced without parents or seeds, is now
also universally exploded.

47. The simplest animals are, like plants, propagated by
slips from the parent, by what is termed gemmiparous pro¬
duction.

The polype is an example of this. From the body of this
animal a small granulation is seen to protrude, which gradually
acquires tentacula and a mouth. Thus attached to the parent
the young continues to feed for some time, until, having
acquired its full development, it drops off, and becomes a
distinct animal. Sometimes other young shoot out from this
one before it has dropped off. These polypes, as well as the
actinia, the common earthworm, and several other animals,
may be artificially divided, and each part will become a dis¬
tinct animal.

48. Animals higher in the scale of organization, produce
spawn or ova, which, like the seeds of plants, contain the
organized germ of the species.

No. 8.

The Physa fontinalis, a small shell snail, common in our
ditches, deposits its spawn on the leaves and stems of plants.
This spawn a consists of a gelatinous mass, in which are seen
minute black spots or ova. In a few days, the influence of
heat and air excite these ova to life, and they gradually
enlarge and become visible as distinct vesicles b, containing the
embryo within, which has now acquired a revolving motion.
A few days more shew the animal with its shell distinctly
formed c; and at last, the embryo d, being perfect, bursts its
enveloping membrane, and makes its escape.

REPRODUCTION.

27

The spawn of the frog exhibits a progressive change of form
of the young animal. At first, it is simply a circular black
ovum contained in a gelatinous mass e. After a few weeks,
it acquires a head, body, and tail, f g h, and bursting its
enveloping membrane, becomes a tadpole. In this condition
it is an aquatic animal, with gills on each side of its head. A
few weeks more, these gills are changed into lungs ; a pair of
fore legs grow out from the chest, then a pair of hind legs
follow, while the tail is absorbed ; and at last the perfect frog
leaves the water, and becomes a terrestrial inhabitant.

Birds are a higher class of oviparous animals. An egg
consists of an external shell, formed of carbonate of lime. This
contains the white or albuminous matter, within two folds of
thin membrane, which separate at the round end, and embrace
within their folds a quantity of atmospheric air. Within the
albuminous matter is the red part or yolk. The germ of the
future chick floats upon the outside of the yolk bag, and is
attached in such a way as always to occupy the uppermost
part of the egg, whatever way this last may be placed, so that
it may be freely exposed to the maternal heat. The chick of
the domestic fowl is developed in this manner :

No. 9.

On the second day of incubation, an elongated body a some¬
what bent, swelled out at each end, and surrounded by a mem¬
brane, the amnion, becomes visible. Traces of a spinal cord
running along this body are first discernible, and then, towards
the end of the second day, several small red points or spots,
the rudiments of the heart and bloodvessels. On the third
day, the heart, in form of a curved canal, is visible, and pulsa¬
tion commences b. The spinal column, ribs, brain, and eyes,
now also can be distinguished. The latter are seen as two
large black points. On the fourth day, the stomach and intes¬
tinal canal are visible. The chorion or umbilical membrane
now also assumes a beautiful appearance, being full of blood-

28

ZOOLOGY.

vessels, which go to supply nourishment to the chick. The
lungs begin to be formed on the fifth day ; and on the sixth,
voluntary motion is perceived. On the ninth day, bone begins
to be formed ; and on the fourteenth, feathers appear c. From
this period to the twenty-first, the whole substance of the egg,
including the yolk, is absorbed into the body of the chick ;
fig. d shews its position in the egg. It now bursts its shell,
and appears an animal perfect in its instincts, and ready to
walk, eat, and perform all its functions.

49. A similar progressive development takes place in the
young of the mammalia previous to their birth, the foetus being
nourished within the uterus by bloodvessels connected with
the parent. The rudimentary vessels, and organs of the foetus,
are first formed double, and afterwards coalesce. It gains an
accession of organs, too, and a change of their form, as it pro¬
ceeds to its perfect state at birth.

A characteristic of the mammalia is, that the young are pro¬
duced alive, and aftewards suckled during a certain period by
milk from the teats of the mother.

SECTION VII.

ORGANS OF MOTION.

50. Besides the organs for the nourishment of the body, there
are others necessary for locomotion, for procuring food, for
defence, and, in the larger animals, for the support and solidity
of the soft parts.

The soft and tender bodies of the lower animals are pro¬
tected and supported by crustaceous and horny coverings, or
by shells, scales, hard plates, or tough skins.

The Terebella conchilega is an instance of a soft and simple
worm forming for itself a sheath of extraneous materials. This
animal burrows in the sand of the sea shore, and consists of a
soft body covered by a thin membrane or skin. From this
skin a mucilaginous and adhesive fluid is poured out, which,
entangling fragments of shells and particles of sand, forms a
protecting case around it.

The caddis worms, or larvae of the phryganea , a brown fly
which is hatched in the water, bv a similar process draw around
their bodies pieces of straws and bark of trees, or the empty
shells of aquatic snails, and thus form a strong sheath for their
protection.

BONES.

20

51. The crustaceous cases of the crab and lobster, and the
horny rings and plates of insects, are in fact external skeletons,
subservient to their protection and locomotion.

The cuttle-fish bone is the first approach to an internal
skeleton.

52. A frame- work of bones, more or less complete, is common
to all the vertebrata.

Bone is composed of phosphate and carbonate of lime, with
animal gelatine. The earthy matter gives it solidity, the
animal matter pliability. Bones are either hollow cylinders,
with articulations or joints at the ends, or plates, with com¬
pact surfaces and a porous centre.

The chief parts of the skeleton are, —

The vertebral column, consisting of cervical, dorsal, and
lumbar vertebrae.

The skull, placed upon this column, and resting on the
first cervical vertebra, consists of the occipital, the frontal,
two parietal, and two temporal bones, with the sphenoid bone
forming the base, and the ethmoid part of the nose. The face
is formed by the two maxillary bones, the palatal and the nasal
bones, and the lower jaw.

The ribs and sternum, forming the cavity of the chest.

The Pelvis, or hollow basin, forming the low’er part of the
abdomen.

The superior extremities, consisting of the scapula or
shoulder blade, the humerus or arm bone, the ulna and radius
the two bones of the fore arm, the carpal or hand bones,
and the fingers.

The inferior extremities, consisting of the femur or thigh
bone, the tibia and fibula, or bones of the leg, the tarsus, or
bones of the foot, the os calcis or heel bone, and the toes.

53. Ligaments connect the jointed bones together, and are
tough membranes, sufficiently elastic to permit of extensive
motion.

54. Muscles are composed of red fleshy fibres, which possess
great elasticity, and by their contraction and elongation pro¬
duce all the motions of the body.

They are either formed of single layers or fibres, all running
in one direction, or of two layers placed obliquely.

Muscles are generally of a deep red colour, constituting the
fleshy parts of animals ; or, they are pale red, as in some
birds ; or entirely white, as in fishes, some reptiles, and in
molluscous animals.

30

ZOOLOGY.

By muscular contractions, every voluntary motion of the
animal machine is performed, as well as the involuntary motions
of respiration, the circulation of the blood, the motion of the
stomach and intestines, &c.

55. Tendons are tough, fibrous bands, which serve to
attach muscles to bones and ligaments. They are joined
to the end of muscles like a rope, and thus form a means of
communication between the muscle and the point from which
it is intended to act. Tendons are most numerous about the
joints, especially the larger ones, where they allow of free and
unrestrained action, and yet occupy little space in situations
where a large swelling muscle would be inconvenient. About
the larger joints of the body, such as the knee, elbow, and
shoulder, there are numerous glands which pour out an oily
substance, that serves to lubricate the joints, and facilitates the
play of the tendons.

56. When we consider tne various positions which the
different parts of the body assume, the agility and quickness
by which the most intricate movements are made, the ceaseless
play of the heart, the heaving of the lungs, and the singular
rapidity of articulation or speech, we need not be surprised
that these muscles should be many in number, and important
agents in the animal economy. There are from four to five
hundred muscles in the human body. On each side of the
back bone there are several layers of strong muscles, which
are fixed by tendons to every projection of the numerous
bones which compose the spine. These muscles keep the
trunk of the body erect, and also permit of the various motions
of the back. There are a number of small muscles about the
face, and head, and eyes, whose various actions impart that
expression to the human countenance which indicates the pre¬
vailing feelings and passions of the individual. The tongue,
besides being of muscular form itself, is supplied by a number
of intricate muscular fibres, which give that amazing volubility
of action, by which the vast number of sounds composing
language are expressed. Several are attached to the lower
jaw ; but two, in particular, the temporal muscles, proceed
upwards through an arch, formed by a projection of the tem¬
poral bone, and are fixed to the scalp. These two muscles
are the most powerful in moving the jaws in the operation
of chewing the food, and are very large in several animals
of prey. Another flat muscle inside the cheek is called
the buccinator or trumpeter muscle, because it assists in

MUSCLES.

31

compressing the cheek in the act of blowing wind instru¬
ments. The chest is supplied with numerous muscles, which
move the ribs upwards and downwards in the action of breath¬
ing. A large flat muscle, the diaphragm, which is attached to
the spine and lower ribs, and stretches across the cavity of the
chest, also contributes to respiration. The arm and hand are
rolled inward and outward, by a set of muscles which are
placed on both sides of the respective bones. The muscles of
the fore arm are fixed to the scapula or shoulder blade at one
end, and to the bone of the arm at the other. The fingers are
moved by muscles situated in the fore part of the arm, and
have long slender tendons by which they are attached.

No. 10.

Two beautiful provisions are
here remarkable : at the wrist
a circular band a binds down the
long tendons of the hand, which
would, in their various motions,
otherwise start up from their
places at the same time that they
play freely below this ring ; the
other is the construction of the
tendons of the fingers. There
are two principal muscles which
move the joints of the fingers,
and two sets of tendons which
are inserted, the one into the
middle bones of the finger, the
other into the third row of bones,
or the extremities of the finger.
In order to preserve their free
action, and to make them lie in
the most convenient manner,
there is a loop or slit in the shorter tendon b, by which the
other passes through to its insertion in the point of the finger c.
Bv this means the longest and strongest muscle moves the
extremities of the finger, where the greatest power is wanted.

The muscles which move the lower extremities are much
of the same kind, but thicker and more powerful than
those of the arms. Several large muscles are attached to
the pelvis and thighs. Two thick muscles compose the

ZOOLOGY.

32

calf of the leg, and are connected at the ancle by the
tendon of Achilles, which is fixed to the heel bone. These
muscles act powerfully in bending the leg, and in supporting
the body while standing or walking. The feet and toes are
moved by several long slender muscles situated in the leg,
which have tendons attached to them similar to those of the
arm and hand.

By the nice balancing of the muscles, and their continual
exertion, man is enabled to maintain an erect attitude, contrary
to the laws of gravity ; and the inferior animals, to stand and
assume their various positions.

Creeping, walking, leaping, flying, swimming, are all modes
of locomotion peculiar to animals.

57. The Fat contained in the cellular membranes fills up
the interstices of the muscular system, and serves to render
the external aspect of the body smooth and symmetrical.

It is secreted in different quantities, according to age, con¬
stitution, sex, and other circumstances, and is absorbed and
redeposited at various periods. In some animals, as in hyber-
nating quadrupeds, it seems to be stored up in seasons of
plenty, to provide against periods of inactivity and inaction.

58. The Skin is a membrane common to almost all orga¬
nized beings, both plants and animals, although in the very
lowest animals, such as the gelatinous polype, the flustra, &c.
it is not very apparent. In all animals above these zoophytes,
however, an external covering of skin is a well marked cha¬
racteristic.

No. 11.

A magnified view of a piece of skin, c the
external cuticle, a the cutis, with the papillae.
Between a and c the mucous net-work, b the
cellular membrane below the cutis, d a hair
with its root and nourishing vessels, e the
sudorific vessels, opening on the hollow fur¬
rows of the external skin.

The skin consists of three parts. The external cuticle or
scarf skin, seems to partake of the nature of a deposition,
being unorganized or unfurnished with vessels, and insensible.
It is variously marked by furrows, in the hollows of which
are numerous minute pores, to permit the exudation of per¬
spirable matter. On the soles of the feet, and palms of the
bands, it is considerably thickened. Below the outer skin is

THE SKIN.

33

the rete mucosum, or mucous net-work, an almost invisible mem¬
brane in the white variety of man, but sufficiently conspicuous
in the negro. This membrane secretes a mucus variously
coloured in the different varieties of mankind ; in the Negro
the pigment is black from containing a portion of carbon.

The cutis, corium, or true skin, lies below this. Unlike the
cuticle, it is highly vascular, containing innumerable minute
blood-vessels and nerves. It is of a bright red colour, and is
acutely sensible to the touch.

The insensibility of the outer skin, constantly exposed to
abrasion and the contact of hard bodies, is a no less wise pro¬
vision of nature than is the extreme sensibility of the inner
skin, which serves as a sensitive guardian for the protection of
the vital parts beneath. The cutis is the most exquisitely
sensitive membrane of the whole body, hence in wounds or in
surgical operations, the greatest pain is experienced when this
membrane is cut through.

Hairs, feathers, down, bristles, grow from the skin, and
form the covering of various animals. All these substances
are bad conductors of heat, and hence their appropriateness as
coverings to animals in cold climates.

59. A hair (fig. 11, d) is a hollow tube, with a bulb or
root enclosed within a capsule, into which the vessels of nutri¬
tion enter. This bulb is situated in the cellular membrane
below the skin, and grows out, as it were, through both
membranes. The central hollow of the hair contains the
carbon, which imparts to it colour, and where this is deficient
or dried up, the hair becomes grey.

60. Feathers also grow out in a similar manner. Each
feather originates in a highly vascular cone, which, after
having nourished the plume, becomes the quill. After the
plume has been completed, the vessels shrivel and dry up in
the interior of the quill.

Horns, nails, and claws are formed of the same material,
(albumen,) and in a similar manner as hair.

c

34

ZOOLOGY.

SECTION VIII.

BRAIN AND NERVOUS SYSTEM.

61. The nervous system is the seat of sensation, by means
of which animals become acquainted with the external world
around them, and through the medium of which instinct and
reason are manifested.

Simple organic life does not seem to require the agency of a
nervous system ; at least, this system is not visibly developed
in plants or the lower zoophytes.

It is very early developed, however, in the progressive scale
of animal existence. In the embryo of all the more perfect
animals, this system is the first to become visible as an orga¬
nized structure ; and branches of nerves or ganglions go to
supply all the organs of nutrition, as well as those of sense or
voluntary motion. Indeed, nervous filaments of some kind or
other pervade every part of the body.

62. The nervous system consists of ganglions, nerves, and
brain. The nervous matter is of two kinds, — a greyish, soft,
pulpy substance, and a white fibrous matter. Both are con¬
tained within sheaths of membranous tissue.

In the polype, and other gelatinous zoophytes, no distinct
nervous system is visible ; but it is not improbable but that
the nervous matter may be diffused among the granulated
bodies which form their structure. The simplest form of
nervous system is that of slender cords traversing the body,
and joining in knots or ganglions. A double
chain of these cords, with ganglions corres¬
ponding to each division of the animal, is
seen in the common earth-worm a, while
from these knots other minute branches are
sent off to the surrounding parts of the body.

In the humble bee b, there is an approach
to the formation of a brain by an accumulation
a b of nervous matter.

a, ganglionic chain As We advance in the scale of animals’ We
of common earth- find a spinal cord giving off nerves and gan-

worm : b, the same glions, and surmounted by a cerebellum or

of humble bee. , ,

lesser brain.

THE BRAIN.

35

No. 13.

the brain of a
fish, d, the brain
of a bird.

63. In vertebrated animals, there is a
cerebellum or lower, and a cerebrum or upper
brain.

In the lower animals, the cerebrum, or
brain proper, is much smaller than in those of
a higher class. In man, the cerebrum, or upper
brain, is much larger, in proportion to the
cerebellum, than in any other animal. It
has also more numerous convolutions or
furrows on its surface than that of the class
of monkeys or quadrupeds which approach
nearest to it in structure.

No. 14.

10 f'

U-'M , |> V i\ I /

ii#I % 7

‘life y '

if

w

35

is

B The human brain, viewed
with the base turned up. a b,
the anterior and posterior lobes
of the cerebrum, c, the cere¬
bellum. d, the olfactory nerves.
e, the optic nerves, ff, the other
nerves of sense taking their
origin from the upper part of
the medulla oblongata, from
whence also proceed the cere-
bro-spinal nerves, g, the spinal
cord, from each side of which
proceed two pairs of nerves, as
at h h.

64. The cerebrum is divided into two halves or hemi¬
spheres. Each of these are marked externally by deep convo¬
lutions. The brain consists of a grey matter, which occupies
the outermost portions of the hemispheres, and a white fibrous
matter, which connects the whole in the centre, and then
joins the spinal cord. The hemispheres have also hollow
internal cavities called ventricles ; one large ventricle occupies
each side, and the smaller ones are common to the brain and
cerebellum.

65. The cerebellum is situated behind and below the cere-

ZOOLOGY.

brum, and internally shews the white fibrous matter ramify¬
ing like the branches of a tree.

At the base of the brain, and at the point where it is joined
by the medulla oblongata , or upper portion of the spinal
cord, the nerves of sense take their origin, d e f From
this part also several branches of nerves proceed to the organs
of nutrition, respiration, &c. These are called the cerebro¬
spinal nerves.

G6. The spinal cord consists of six filaments, all included
within one membranous sheath.

From the anterior portion of the cord, two pairs of nerves
branch off at short intervals along its whole length, and send
filaments in all directions over the body ; these are the nerves
of motion, h h. Two nerves are sent off at the same time from
the posterior part of the spinal column, which accompany the
others, and are the nerves of sensation.

SECTION IX.

THE ORGANS OF SENSE.

67. By means of the senses, animals become acquainted
with the external world, and with the properties of bodies
around them. They are five in number, — touch, taste, smell,
hearing, seeing. For each of these senses there are appro¬
priate organs, and these organs must be acted upon, more or
less directly, by matter from without, before an impression is
conveyed to the seat of perception.

68. All the senses are not indiscriminately bestowed upon
every gradation of animals, a great proportion of the lower
classes being destitute of one or more of them. Man and the
•more perfect animals alone are furnished with the five senses,
by which they are enabled to distinguish all the qualities of
bodies.

In order to have a complete knowledge of an object, every
one of the senses is requisite, for each imparts some informa¬
tion different from the other. Thus, the sight of an apple
conveys to us only the idea of a plane circle, with a surface of
varied colours. The touch of this apple informs us that it is
a sphere, with a certain degree of smoothness or roughness on
the surface. From the sound pioduced by striking it, we may
ascertain whether this sphere be hollow or solid within. The

TOUCH. 37

smell gives us the peculiar odour ; and the taste another of its
important properties.

69. The Sense of Touch, or feeling, may be said to be
common to all animals ; for this is a distinguishing characteristic
of animated beings, that they possess sensation in contradis¬
tinction to the mere irritability of plants. The simplest
zoophyte shrinks when a sharp body is applied to any part of
its frame ; and so sensitive is the common earth-worm, that it
perceives the tremulous motion of the earth, withdrawing
itself into its hole when an enemy approaches, and coining
forth to feed when it feels the soft drops of rain pattering on
the soil.

70. This sense is diffused over the whole body, though
very unequally ; and, indeed, in many animals which are pro¬
tected by horny or crustaceous coverings, the perception of
feeling in any of the external organs must be very obtuse and
imperfect.

The general diffusion of a certain degree of sensibility, how¬
ever, is bestowed on all animals, to warn them of danger, of
the contact of opposing bodies, of extremes of heat or cold, of
moisture, or of deleterious fluids. So universally spread
over the surface of the body are the nerves of feeling, that one
cannot touch the minutest spot with the point of a pin without
exciting some of them. It is not improbable but that there
are more than one set of these nerves, as the feeling of cold or
heat is sometimes perceptible when the contact of sharp
pointed bodies is not distinguishable.

The sense of touch resides in the cutis, the papillte of which
are formed of extremely minute arteries and branches of the
nerves of sensation. (See fig. 11, a.) The external cuticle
is itself insensible. The sense is most acute in the tips of the
fingers, the lips, the face, the arm-pits, and less so on the
trunk of the body, the head and joints.

A simple experiment will shew this. Take a pair of
metallic compasses, and separate the points to one tenth of an
inch. If you apply these to the arm or the cheek, you have
the perception of only one point of contact, whereas if you
apply them to the lips or the points of the fingers, the superior
sensibility of these organs will distinguish two distinct points.
If you separate the points of the compass an inch asunder, and
draw them along the cheek from the ear to the mouth, you
fancy that the points separate wider and wider as you approach
the more sensitive parts, while, by reversing the operation,

38

ZOOLOGY.

you have the feeling as if the compasses were gradually
closing.

Nature has established a beautiful and most appropriate
adjustment of the sensibility of the various structures of the
body. Thus, though the external skin or cuticle is insensible,
the cutis or inner skin is highly alive to all external injury.
The muscles are much less so ; the tendons only become sen¬
sible when over-stretched ; the bone only when inflamed or
diseased ; the vital organs, as the heart, lungs, brain, have
very little sensibility ; the membranes of the eye are exceed¬
ingly sensitive of the irritation of small particles of matter, as
dust, hairs, fluids, but can bear the application of the finger
without indicating any extraordinary irritability.

71 . Some animals of prey have hairs or bristles projecting from
their mouths, which communicate the contact of bodies to the
sensitive skin : such are the whiskers of lions, cats, and dogs.
Bats have a singular acuteness of touch, by which, in flying
through dark passages, they can avoid projecting corners and
other obstructions in their unseen course.

72. All the other senses may be said, in some degree, to
be modifications of touch, as all the organs of sense are stimu¬
lated by the immediate contact of matter. Thus sapid bodies
touch the tongue ; odoriferous particles touch the membrane
of the nose ; undulations of air cause vibrations of the tym¬
panum ; and light stimulates the nerve of vision.

73. The Sense of Taste is in general confined to the
tongue, and resides in the raised papillae, which are found
covering its upper surface, especially towards the middle and
point. These papillae are formed by blood-vessels and the
branches of the gustatory nerve.

In man and most of the mammalia, the tongue is the sole
organ of taste. If you touch the lips, or palate, or cheek
with a piece of sugar, no sensation of sweetness is perceived
till you apply the tongue to the part so touched.

In many birds, in insects, and crustaceous animals, where
the tongue and mouth are not formed of soft parts, but are of
cartilage, horn, or shell, the sense of taste must be very
imperfect, if not altogether deficient. Some animals are sup¬
posed to possess this sense in the lower parts of the esophagus, or
in the stomach. As in a great proportion of the lower animals,
however, this appears the only sense which could guide them
in the selection of their food, taste, under some modification or
other, must be one of the most universally diffused of the senses.

SMELL. 39

74. The Sense of Smell resides in the nose, or inner
lining of the nostrils.

No. 14.

» is a section of the cavity
of the nose, separated into
two parts by the septum.
o the olfactory nerve, with
its branches ramifying on
the inner nostrils. The ca¬
vity of the nose communi¬
cates with the mouth at u,
where is situated the uvula
or little valve, seen in the
back part of the mouth,
which guards this passage to
the nostrils.

The internal cavities of the nose present a large extent
of surface, by reason of numerous plates or divisions of the
thin bones composing the organ. The surface of these plates
is lined by a mucous membrane full of bloodvessels, and over
which the branches of the olfactory nerve, o o, are dis¬
tributed. Many bodies emit an effluvia or odour, which is a
portion of their substance diffused in the air, in the form of
exceedingly minute particles. Before an odour is perceived,
it is necessary that a current of air, containing these minute
particles, should pass through the nostrils, for if a person
remains perfectly still, without breathing, no smell is percep¬
tible.

75. The sense of smell is very acute in some animals,
serving the important purpose of guiding them to their food,
or enabling them to escape danger. Certain animals of prey,
as bears, wolves, and dogs, hunt by means of their acute scent,
and wild buffaloes, deer, and other herbivorous quadrupeds,
smell the approach of an enemy at a great distance, and imme¬
diately provide for their safety in flight. The simpler classes
of animals, as shell-fish, snails, worms, have no organ of
smell, and are thus incapable of perceiving odours. In man,
the sense adds to his enjoyments, and enables him to avoid
poisonous food and noxious vapours, which would prove fatal
to him.

76. The Sense of Hearing. The ear is the organ of
hearing, and is much more complicated than the organs

40 ZOOLOGY.

hitherto enumerated. The external ear is an oval hollow,
marked by several convoluted passages, for collecting and
transmitting into the interior ear the undulations of the air.

No. 15.

E the external ear. a the passage to the internal ear. b the membrane of
the tympanum, c d, the small bones of the tympanum, f the semi-cir¬
cular canals, g the cavity of the cochlea, and auditory nerve seen entering
it above, h the eustachian tube leading to the mouth.

The internal parts of the ear are situated in a hollow of
the temporal bone. A pasaage leads directly from the outer
ear to this inner cavity. In order to prevent extraneous
bodies from entering this passage, it is furnished with nume¬
rous hairs and a tough wax, which envelops dust or other-
bodies, and deters, by its disagreeable, bitter taste, insects
from penetrating through it. Around the mouth of the inner
tube, is a circular hollow, called the tympanum, over which is
stretched a thin membrane or drum. Behind the tympanum
the passage is still continued. Above are the hollow semi¬
circular canals, and a little farther onwards the cochlea, a
cavity like the interior of a convoluted marine shell. These
cavities contain a fluid matter, and here the branches of the
auditory nerve are distributed. Four little bones are adjusted
by small muscles to the margin of the tympanum, and seem to
be instrumental in stretching or relaxing the membrane, to
accommodate it to feeble or strong vibrations of the air, as well
as to transmit these vibrations to the inner chambers of the
ear. The eustachian tube forms a passage of communication
between the internal ear and the mouth, its lower end opening
upon the side of the cheek behind the passages to the nose.
The use of this opening is to allow the exit of air from the
inner cavities of the ear, and thus to permit of a free vibration

HEARING.

41

of the membrane of the tympanum. Hence, in a common
cold, when there is inflammation and obstruction of this
cavity, deafness occurs.

AVe have thus an organ, curiously contrived, to collect and
transmit vibrations to the sensorial nerve ; the next considera¬
tion is the cause of sound.

77. All bodies, especially elastic ones, when they come into
sudden contact, vibrate or move quickly backwards and for¬
wards ; this produces a wave-like motion in the air, and these
waves or vibrations exciting the organ of hearing, convey to
us the impression of sound. This aerial undulation may be
explained by what takes place in dropping a stone into a pool
of water. Immediately around the stone the water becomes
agitated, and circle after circle of waves expand and roll on
till they reach the margin. Thus the vibration of a piece of
wood struck against a resisting body, the vibrations of stringed
or wind instruments, or of the elastic membranes of the throat
and mouth of animals, or the explosion of a gun, or the con¬
cussion of electric matter in the clouds, all produce an impulse
in the elastic air, and become the cause of sound.

78. These successive undulations take a perceptible time to
flow onwards. Sound is calculated to travel at the rate of
eleven hundred feet in a second, or about one mile in four
seconds ; and as vision may be said to be instantaneous, the
report of a gun fired at the distance of a mile, is not heard till
four seconds after the flash has been perceived. Thus, too,
in looking at a distant workman hammering on a stone or
anvil, the report seems to be produced when the hammer is
elevated in the air, at an interval of several seconds after the
blow has actually been struck.

While ordinary sounds are perceptible only within a limited
space, violent and extensive concussions of the atmosphere,
with favourable winds, may be heard at the distance of twenty,
fifty, and even one hundred miles.

Water and solid bodies, as wood, and the surface of the soil,
are better conductors of sound than the air.

79. A great proportion of the lower animals are destitute of
an organ of hearing ; and hence we may conclude that they have
no perception of sound, properly so called ; yet many of these
have such extreme sensibility of feeling, as to be quite alive
to the aerial vibrations that give rise to sound in the higher
classes.

In animals of prey, the sense of hearing is extremely acute.

ZOOLOGY.

42

In the feline species it is particularly so. In the owl the
organ is very largely developed.

80. The Sense of Sight, is the most varied and splendid
of the whole, and embraces a field which is only bounded by
the material universe.

While the other senses are confined to bodies which come
into immediate contact with us, or which exert their influence
at a short distance, vision acquaints us not only with the
minutest atoms which float in a drop of fluid, but also with
the shapes and motions of other worlds, and other suns, which
lie far beyond any conceivable limits of distance.

81. The eye is of a spherical form, and is situated in a cor¬
responding hollow formed by the bones of the head and face.

Fig. 1. No. 16. Fig. 2.

Fig. 1. — b b, lacrymal points, leading by the duct a to the nose, i, the lined
circle the iris, the black circle the pupil.

Fig. 2. — mm n, muscles which move the eye-ball, c, cornea, i i, iris.
p, the pupil. I, crystalline lens, o, optic nerve.

It is composed of three coats — the sclerotic or external coat
forming the white part of the eye, the choroid or middle coat,
and the retina, or fine nervous net-work, which lines the inner
cavity. Three-fourths of the ball of the eye are hid within the
bony socket ; here, too, are placed the muscles which move it
in all directions. There are six of these muscles m m, which
produce the various movements of the eye. They are
attached to the eyeball, and to the bones of the socket.
One of these muscles has its tendon passing over a loop or
pully in the socket, fig. 2, n, an evident contrivance to double
up this muscle, which would otherwise be too long for the
space in which it has to play, while at the same time it reverses

VISION.

43

the direction in which the muscle acts. The eyelid forms a
moveable protection in’ front, and the eyelashes prevent the
intrusion of small bodies. As the membranes of the eye
require to be kept constantly moist and transparent, a gland in
the upper and outer angle of the socket secretes a fluid for
this purpose. After this fluid has moistened all parts of the
eye, it flows into two little ducts or openings, b b, seen in the
inner corner of each eyelid, and thus passes into the cavity of
the nose by the canal a. When produced in excess, this fluid
is called the tears.

A front view of the eye (fig. 1.) exhibits the sclerotic coat, or
vuter white circle ; the cornea, or next circle, which is trans¬
parent, and through which is seen the iris i, or moveable curtain
of the eye ; and in the centre, the pupil or window, through
which we look into the back chamber.

A side view or section of the eye (fig. 2) shews the position
of the same parts. The cornea c is a semicircle, projecting
in the middle ; the membrane is quite transparent, and the
fluid within is called the aqueous fluid ; i i, is the iris. This
membrane is so called because it is of various colours in diffe¬
rent individuals. It is of a muscular structure, and is so sen¬
sible to the stimulus of light, that its fibres contract whenever
luminous rays fall upon it. In this way it modifies the quan¬
tity of light which enters the eye. In a feeble light, the iris
relaxes, so that tlfe pupil p is greatly enlarged or dilated ; in a
strong light, it contracts and diminishes the circular opening
of the pupil to a mere point.

Behind the iris is seen the crystalline lens l, enclosed within
a capsule or case, which is kept in its position by the ciliary
processes. The lens is doubly convex, with the greater con¬
vexity behind. It is filled with a dense fluid, called the crys¬
talline humour. The structure of the lens is lamellar, many
thousand exceedingly thin plates entering into its composition.
This structure may be seen in the eye of a fish after it has been
boiled. Behind the lens is the posterior chamber of the eye,
occupying the greater part of the ball, and filled with the vitreous
humour, a dense transparent fluid. The optic nerve o enters
the back chamber of the eye, and spreads out into an
extremely fine net-work, upon the retina or inner lining.
Below this, a layer of carbon forms a black pigment, which
prevents all reflection of the rays in this inner chamber.

82. The theory of vision is this : Light falling in direct
rays from the sun is reflected from the surface of bodies, and

ZOOLOGY.

44

thus comes to the eye in straight lines from every point of the
objects before us. The eye collects these rays ; and they first
enter the cornea, from whence they pass through the central
opening of the iris, subject to the control of this highly sensi¬
tive organ. Arriving at the lens, they are refracted by its
convex surface, and passing through the vitreous humour, are
conveyed into a focus on the retina or back chamber of the
eye. Here a minute image of the object before the eye is
painted, and thus- the impression is conveyed by the optic
nerve to the sensorium. There are two circumstances which
may here be noticed. The picture on the retina is reversed,
yet we perceive it in its natural position ; and there are two
images, one on each retina, yet our perception is so modified
as to impart to us but one ; although sometimes, in cases of
disease, two distinct objects are visible. The picture on the
retina must be inconceivably minute, as we can embrace, at
one view, a whole district of country, and can watch an object
in motion — a horseman, for instance — travel over many miles
without our ever changing the axis of vision.

The form of the cornea influences the focus of vision. A
flat cornea or small convexity impedes distinct vision of near
objects. This diminished convexity is a usual accompaniment
of old age. A too convex cornea, on the other hand, prevents
distinct vision at a distance, giving rise to near-sightedness.
Hence, in the use of spectacles, a convex lens corrects the flat
cornea, while a concave aids the cornea, which is too much
rounded.

It is supposed that the cornea, or some other portion of the
eyeball, is capable of changing its form somewhat to adapt its
focus to near or to distant objects. The marsupium of some
birds appears conducive to this adaptation.

The aqueous fluid of the cornea, the crystalline of the
lens, and the vitreous of the posterior chamber, are each of
different densities ; and thus the eye becomes what opticians
call achromatic — the coloured rays of refracted light are
remodified into one colourless mass before they fall upon the
retina.

There is a close resemblance between the structure of the
eye and the most perfect telescope. Yet the latter was not
formed after the model of the former. The telescope was
purely an artificial invention ; and the perfecting of its parts,
especially the introduction of plates of glass having different
densities into the lenses, by which they became achromatic,

VISION.

45

was the result of experiment and deduction. How singularly
does this prove the unity of design and purpose which per vades
all nature ! Man, endowed with reasoning powers, comes to
the same conclusions which the Great Reasoning Mind had
conceived in the beginning of time ! The creature of the dust
shews intimations of his original formation in the image of his
Maker !

83. Sight, in all that relates to the actual size of bodies, is
the most deceitful of the senses. Objects decrease rapidly as
they recede from the eye. At the distance of one hundred
yards, a horse appears actually no bigger than a rat ! A blind
boy, who was restored to sight by Cheselden the oculist, on
first looking out on the streets, shouted to his friends to come
and see four rats running off with a box. This was a coach
and four, the real dimensions of which were entirely unknown
to him from previous experience. The sense of touch and the
knowledge' of distance alone correct our sense of vision. In
man this knowledge is acquired. In animals it is instinctive
and perfect at birth.

84. Vision is denied to many of the lower animals — to
zoophytes and a great proportion of the mollusca. Insects are
amply supplied with numerous visual discs. The vertebrata
are almost all endowed with vision. There are some singular
exceptions, however, as the blind rat, ( marmota typlus .) The
proteus, a reptile living in the subterranean lakes of Illyria,
is destitute of eyes ; and yet Nature, to preserve her chain of
analogies, has given the form of eye-balls in its head.

In predaceous animals, vision is generally acute, especially
among birds, as the eagle and falcon, which single out and
dart on their victims from a great height in the air. Vultures
perceive their prey at the distance of many miles, before its
odour could reach their nostrils ; and thus they fly at once and
in a direct line to their feasts of dead and putrifying carcasses.
The linear pupil of some animals, as the cat tribe, allows of a
greater expansion of the iris, and thus they distinguish objects
with very little light.

The loss of sight is the greatest deprivation which can befal
an active and intelligent mind. Milton makes Samson feelingly
exclaim, —

Oh why was sight

To such a tender ball as th’ eye confined,

So obvious and so easy to be quench’d,

And not, as feeling, through all parts diffused,

That she might look at will through every pore !

ZOOLOGY.

46

85. Sleep is a temporary repose, and, in a great degree, a
suspension of the nervous functions. Thus the senses are
lulled to rest, as well as the muscles dependent upon the will,
and all the functions which have been termed relative. The
nutritive functions continue, but under a diminished influence.
The breathing and circulation are both slower, and thus the
animal heat becomes diminished ; digestion and assimilation,
though they still go on, are not so vigorous as in the waking
state.

It is probable, that all animals, even the lowest, experience,
more or less, this suspension of their powers ; while, in the
higher classes, where the nervous system is more perfect,
sleep, at stated and regular intervals, is as indispensable as
food or air. After repose, the tired-out muscles and exhausted
mind feel again invigorated and refreshed ; and hence the
poet has not inaptly termed sleep the “ chief nourisher in life’s
feast.”

86. All the ordinary stimulants of life, pushed to excess,
have a tendency to induce sleep ; as excess of heat or cold, too
much food or fermented liquors, exercise in the open air.
The absence of one or more of the usual stimuli also, by
inducing debility, has the same effect. Excessive indulgence
of sleep induces torpor, obesity, and inactivity of mind and
body.

Young animals require more sleep than old, and certain
temperaments or constitutions can do with much less sleep
than others.

87. The torpidity of certain animals during winter seems to
be induced by a diminished temperature acting on a peculiarly
constituted system. Such animals are said to hybernate, as
the bat, hedge-hog, badger, &c.

88. Dreaming arises from the mind thinking without the
aid of the senses. Hence the incongruity of dreams, and the
inconsistency of every thing in them that regards time, place,
and circumstance. Dreams seem often to be repetitions of the
same trains of thought which had occupied the waking hours
of the day, only much confused and distorted ; or they may
arise from faint impressions conveyed through the medium of
the lulled senses awakening a confused recollection of past
occurrences.

Thus a bottle of hot water applied to the feet suggests ideas
of a volcanic mountain, while cold applications give rise to
visions of Alpine snows or chill waters. The sound of a falling

TEMPERAMENT.

47

body will seem the roar of a cannon, and may give rise to
dreams of battles, or of attacks of highwaymen. Excessive
thirst and dryness of the throat suggest gushing streams or
cool delicious fruits. Of all the senses, that of smell seems
less frequently an originator of our dreams, and consequently
is seldomer mixed up with them.

Dogs, parrots, and other animals, are said to dream, as they
not unfrequently scream and use convulsive motions during
their sleep. We must be very cautious, however, in deter¬
mining whether all these arise from mental impressions, or
whether they are not simply convulsive movements of the
muscles of the throat and extremities, such as frequently
take place in human beings, without any accompanying
dreams.

If we suppose that animals dream, we grant them the power
of forming abstract ideas independent of external impressions,
and thus assimilate them with intellectual man. (92.)

SECTION X.

TEMPERAMENT.

89. A certain constitution of the individual, whereby his
bodily structure and functions, 'as well as his mental disposi¬
tions, are influenced, has been termed the temperament.
Certain relative proportions between the digestive, absorbent,
respiratory, and nervous organs, would appear to give rise to
temperament.

Thus, when the digestive, assimilative, and bilious functions
predominate, a certain habit, called the bilious temperament, is
present ; when the respiratory and sanguiferous, the sanguine ;
when the brain and nerves, the nervous.

90. Several combinations and modifications have given rise
to corresponding denominations.

The characteristics of these temperaments are shortly
these :

Sanguineous.

f Fair, florid complexion ; figure tall, plump ; auburn
l or light bid? ; blue eyes, transparent skin ; quick per-
I ception of intellect ; memory tenacious ; lively imagina-
- tion, disposed to hope ; versatile, active, impassioned ;
generally healthy, but tendency to inflammatory com¬
plaints. If the mental powers are inferior, an athletic and
, muscular body.

48

ZOOLOGY.

Bilious

Nervous.

f Complexion dark, hair black, features well formed and
) expressive ; muscular system firm and powerful ; intellect
I bold and adventurous, firm, courageous, passionate ; liable
V to affections of the digestive organs and liver ; melancholy.

{Countenance pale ; head proportionably large ; muscular
system soft, flabby, sensitive ; mind highly intellectual,
but variable, irresolute, irritable.

A due balance between all these produces the most perfect
animal manifestations. That temperament prevails among the
human species, giving rise to individual character, national
peculiarities and varieties of the race, is abundantly evident,
as well as that indications of the same thing are visible among
many classes of the inferior animals. AVe often find individual
animals characterized by peculiarities of body, and also temper,
which does not universally belong to the species of which he is
a member.

The temper or disposition of horses, dogs, sheep, hares,
and many others, vary in individuals, nearly as much as in
man.

The physiognomy often indicates the temperament in man
and animals. Besides the muscles of the face, which have a
tendency to assume the form and position which they are
ofter.est thrown into by the prevailing passions of the mind,
there is a lustre of the eye, a tint of the skin, and a varying
hue of the features, which all indicate the operations of the
passions within.

Instances of this kind are observable every day in the first
interview of strange dogs or other animals.

Every person, too, forms an opinion of another at first sight,
and these natural impressions are for the most part correct,
and at all events influential.

SECTION XI.

INSTINCT.

91. Besides the nutritive functions, which are unceasingly
and unconsciously at woik in the animal machine, and by
which the individual is preserved, and the species multiplied,
there are others called instinctive, which guide the animal to
its food, its preservation from the weather, and from external
injuries, and enable it to provide for the comfort of its tender
offspring.

INSTINCT.

■19

The ordinary degree of this instinct seems to he very analo¬
gous to the nutritive functions, which we have alluded to, and
would seem to be an extension of the same vital laws which
pervade the animal economy. The untaught impulse which
directs the young calf to its mother’s teat, the newly hatched
chick to pick up seeds, or peck at a passing fly, or which makes
the bee of a day old perfect in building its cell, or in gathering
honey, and flying in a direct line to and from the hive, appears
to differ in degree only from the digestive, the circulating, or
the secreting operations, which are at the same time set in
action within the animal.

These simple instincts are common to all animals, even the
lowest ; but as we advance in the scale of being, and as the
nervous system becomes more complete, the instinctive mani¬
festations also become more perfect, till at last they merge into
something like deliberate and rational acts.

92. It is extremely difficult, then, to define the exact nature
of instinct, or to draw a line of demarkation between it and
reason. By instinct is understood that governing impulse in
animals, by which they perform all those operations necessary
for their limited sphere of existence, in the fittest and most
direct manner, without instruction, experience, or forethought,
and which is perfect from the first, and cannot, beyond a very
limited degree, be extended in the individual, while it admits
of no progression in the species.

Animals have been considered by some as mere machines,
performing actions, like automatons, either under the imme¬
diate direction of a superior intelligence, or so contrived at the
beginning as to perform a certain invariable round of uncon¬
scious operations. Others have supposed them really conscious
beings, and have endeavoured to separate their actions into
instinctive, and deliberative or rational.

Thus, an ant instinctively hoards up grain, but when she
bites off the germ to prevent its growth, it is said to be a
rational act. A crow instinctively picks the animal out cf a
sea shell, when it happens to be so protruded as to allow of its
being seized hold of ; but when the crow takes the same shell,
when shut, high up into the air, and lets it drop on a rock,
in order to break the covering of its hidden prey, the action is
said to be deliberative. A young greyhound instinctively
follows the doubling of the hare, but, when old and experienced,
he cunningly crosses by a short cut, in order to intercept his
prey. Now, in all these, and a number of similar instances,

D

5 )

ZOOLOGY.

may not the acts called rational be just as much instinctive as
the others ? Animals are evidently endowed with a variety oil
instinctive resources, suited to the varying circumstances under
which they may be placed ; and it is just when these circum¬
stances occur that the suitable instincts are called into action.
If many of the so-called rational acts of animals be really
the result of deliberation and forethought, they are singu¬
larly wise and prudential, and would indicate a high degree
of intellectual acumen. But these acts are confined to a
few particulars connected with a narrow range of the animal’s
wants, and the preservation of its young ; in all other respects
it is stupid and improvident. This differs entirely from the
reason of man — it is comprehensive, is derived from the collected
experience of innumerable facts, and if acute in one department,
is not deficient on the whole.

Animals seem impressed by matter alone. Their instinctive
impulses are awakened and stimulated through the direct
medium of the senses, either by external causes, or by some
unknown changes which take place within their own bodies.
They appear to be incapable of forming abstract ideas, or of
having their volition stimulated without the impress of matter
on their senses.* (See 88.)

The instincts of animals seem very much guided by the high
degree of perfection of one or more of their senses. Thus the
antennoe of insects possessing touch, and perhaps other modifi-

* Accurate and authentic observations on the manifestations of the instincts
of animals are very much wanted. In general, observers are too apt to mix
up with their investigations and descriptions human prejudices, and thus to
impart rational motives to actions in which perhaps reason had no share.
Thus we have well authenticated stories of dogs, horses, and parrots, which
would shew all these animals to be possessed, not only of a good share of
wisdom, humanity, and discretion, but also of fine taste, wit, and repartee.
Ah uno disce omnes. Prince Maurice saw in Brazil a wonderful parrot,
with which he held the following conversation, through an interpreter, for he
could not speak Brazilian: — “From whence do you come?” “From
Marinnan.” — “ Who do you belong to ? ’’ “ To a Portuguese.” — “ What do
you do there?” “ I look after the chickens.” — The prince laughed, and
said, — “ You look after the chickens ?” “ Yes ; and I know very well how
to do it,”— making a chuckle four or five times, as people do who call poultry
to them.— Sir IF. Temple, quoted by Locke.

When Colonel Kelly and his parrot were at Brighton, the bird was asked
to sing : he answered, “ I can ’t.” Another time he left off in the middle of
a tune, and said, “ I have forgot.” The parrot took up the bottom of a
lady’s petticoat, and said, “ What a pretty foot !” The company teased and
moped him a good deal : he said, “ I don ’t like it.” — Jesse, from a memo¬
randum found amongst the late Earl of Guildford's papers.

INSTINCT.

51

cations of sense, in an exquisite degree, are the organs by which
their instincts are chiefly influenced. Dogs derive impressions
from their acute sense of smell, more than from their other
senses ; and vultures, eagles, and birds generally, have exceed¬
ingly acute vision.

93. Not only are animals guided and influenced by impres¬
sions on their senses, which in many are of the most exquisite
kind, but they are also possessed of feelings and emotions,
and sympathies akin to those of human beings.

That animals are susceptible of emotions and passions is
abundantly evident. We find strong attachments subsist
between individual animals, and between some animals and
man. They experience not only pleasure and pain, but joy
and grief, fear and hope or expectation, surprise, wonder,
anger, jealousy, pity or commiseration, a love of approbation,
and shame, if not regret. Thus, horses that have been accus¬
tomed to feed in company, lose their appetite, and fall off in
flesh, when confined in a solitary stable. The separation of
two fondly attached animals has even caused death. The
devotion of a dog to his master is daily to be witnessed. A
pointer, on leaving home with a sportsman, evidently seems to
anticipate the pleasure of the coming sport. A strange or
unusual object readily excites the wonder of an animal. The
minute and ceaseless curiosity of the monkey, and many other
tribes, are also very apparent, and irritation and offence readily
excite anger. When a sea-gull is shot dead, his fellows
linger and wail around him. Most animals are fond of being
caressed ; and a dog actually shews shame, or a consciousness
of having committed a fault, for which he is reproved.

Memory, too, or recollection of past impressions, is also
very strong in many animals.

94. Man has also instincts, and emotions, and sympathies,
like the lower animals, but to these he has superadded reason
in its proper acceptation. Man’s actions and impulses, except
in early infancy, are guided by judgment and reflection. His
operations arc the result of experience and education. He
alone has true consciousness of his existence, of his relation to
a Higher Power, and of his moral responsibility for his actions.
His knowledge of physical nature is derived from his senses ;
but he can also form abstract ideas, and think and reason
without the immediate aid of external impressions. In him
memory extends not only to the revival of past impressions of
sense, but also to the recollection of ideas, and to the accu»

ZOOLOGY.

52

mulated experience of long past ages. Imagination, too, can
form out of the impressions of the past, an infinite number of
combinations, and create in thought, and embody in words,
what never had an actual existence. All other animals are
prone and grovelling. They live and die, and leave no
memorial of existence. Ere man was created, the world was
incomplete :

There wanted yet the master-work, the end
Of all yet done, — a creature who, not prone
And brute, as other creatures, but endued
With sanctity of reason, might erect
His stature, and upright, with front serene,

Govern the rest, self-knowing, and from thence
Magnanimous, to correspond with heaven. — Milto

The sensations, emotions, and sympathies, also act as so
many stimuli on the animal frame. Fine music, and beautiful
sights, are no less exhilarating than food and warmth. The
beneficent Creator,

Not content

With every food of life to nourish man,

Hath made all nature beauty to his eye,

And music to his ear.

We have already alluded to the emotion of attachment in
influencing the health and even the existence of animals.
Loved companions and cheerful society are the greatest zests
of intellectual existence. Anger, revenge, and grief, are more
deleterious than poisons. Joy stimulates even sometimes to the
extinction of life. The animal machine therefore becomes still
more wonderful the more we consider it. Not only is it stimu¬
lated by material agencies from without, but within itself
emotions and sympathies arise, which react on the system
from whence they spring ; and, according as they are in mode¬
ration or excess, produce pleasure and pain : they fan and
invigorate the flame of life, or they extinguish it altogether.

SECTION XII.

CLASSIFICATION OF ANIMALS.

95. Considering the great diversity of forms which we find
existing in animated nature, giving rise not only to marked

CLASSIFICATION.

53

divisions of beings, differing widely from each other in appear¬
ance and habits, but even to minuter shades, constituting
innumerable species, it must be evident that in order to study
or describe them, some arrangement or classification is abso¬
lutely necessary.

Nature has so far made this classification ; but as in her
scale of being she does not altogether proceed in a straight
line, blending every order, and class, and family, by a pro¬
gressive imperceptible gradation, neither are her links or
circles of natural groups, of which her chain is made up,
always complete, or in exact accordance one with another — it
follows, that any arrangement, however philosophical, must be
so far imperfect, and partake both of a natural and artificial
character.

There are certain leading denominations common to all
arrangements.

DIVISIONS

CLASSES

ORDERS
GENEBA .

BUBGBNBRA
SPECIES .

Varieties . . .

Mark out the great leading distinctions of the whole
animal kingdom.

Comprehend groups which have certain characteristics
in common.

Are groups contained within certain classes.

Are families of orders having certain common marks of
resemblance.

Are offsets from families.

Are certain members of families having an exact
resemblance of all their parts, so that every indivi¬
dual of this denomination is a counterpart of
another.

Individuals of a species having slight differences of
unimportant character.

Every animal has two scientific names, — the generic and
specific ; the one pointing out the family to which it belongs,
the other the branch or species of which it is an individual
member. Besides these, there is a trivial or local name gene¬
rally superadded. If the animal is well known, and an inha¬
bitant of a wide range of country, several of these names, both
scientific and trivial, are bestowed upon it : hence originate
synonymes. Thus felis is the generic name for lions, tigers,
cats ; and felis leo, the lion, felis tigris, the tiger, point out the
species. This genus belongs to the order Carnivora, to the
class Mammalia, and to the great division Vertebrata.

64

ZOOLOGY.

SECTION XIII.

I. DIVISION — VERTEBRATA.

56. The animals of this division are characterized by having
a frame-work or skeleton of bones* which gives support to the
body, and permits of extensive locomotion.

The vertebral column or spine is the most conspicuous part
in the skeleton, and is common to all the classes of the divi¬
sion. It is composed of a series of joints or vertebrae, through
which passes the spinal cord, in a canal common to the whole.

All the members of this division have a brain and nervous
system, the five senses, a heart and blood-vessels with red
blood, and either lungs or gills. The body is symmetrical, or
composed of two halves, and most of its parts and organs are
double. In this division there are four classes :

I. Mammalia.

II. Birds.

III. Reptiles.

IV. Fishes.

CLASS I. — MAMMALIA.

97. This class is so denominated because the young are pro¬
duced alive, and suckled for a certain time by milk derived
from the mammae of the mother.

The members of this class, though the least numerous, are
the most important, and, in general, the largest in size of all
the animal kingdom.

ORDER I. BIMANA, Two-Handed.

98. At the head of this class is man, forming a distinct order
and a single species.

The physical structure of man differs from that of all other
animals, in being adapted for the erect position. For this
purpose, his foot is so formed that he treads directly upon its
sole ; the pelvis is broad, and furnished with large and power¬
ful muscles, which extend along the thigh ; and the head,
which is large, from containing an expanded brain, is placed
on the vertebral column, so as to be supported in an upright

MAN.

55

position. The arms possess extensive and free motion,
and the hand is so formed and supplied with muscles, that
every joint of the fingers and thumb is possessed of motion.
This complete muscular power, joined to the fine sensibility
of touch imparted by numerous nerves and bloodvessels,
renders the hand of man superior to any organ of the inferior
animals.

Although in muscular power, and in the acuteness of some
of the senses, man is surpassed by several animals, yet, on the
whole, he may be said to excel in the completeness of his
general organization. He can endure long continued exertion,
extremes of climate, a low or elevated situation, and all the
circumstances attending a diversity of geographical position,
better than any other of the inhabitants of the globe. As
possessing reason and the faculty of speech, he is also
removed to an immeasurable distance from brutes.

From the structure of his teeth and digestive organs, man
seems to be allied to those animals that feed on fruits, nuts,
and the roots of vegetables ; but the art of cookery enables
him to convert almost every substance in the animal and vege¬
table kingdoms to his nourishment. He has hence been
called an omnivorous feeder.

Man differs from other animals in his long and helpless
infancy and childhood, which has evidently been intended to
promote his moral and intellectual culture, and to imbue his
mind with those feelings of maternal and domestic attachment,
which tend so much to promote the stability of society.

99. There is such a general and particular resemblance of
the anatomical structure in all races of mankind, and such an
identity in the performance of their animal functions, as prove
that all belong to one species ; thus confirming the historical
account of a single pair having been the progenitors of the
whole human race. Yet there are certain peculiarities among
these which have led to the division of man into varieties.
This tendency to pass into varieties prevails throughout all
organized nature. It is seen in plants, and more especially in
those species which undergo changes of soil, climate, and
culture. In animals it is also remarkable, in those particu¬
larly which have been domesticated by man ; as sheep, horses,
dogs, pigs, and cattle. So great are the changes brought
about in these, in regard to size, colour, and the form of their
limbs and bodies, that it is sometimes difficult to believe that
all the extremes have sprung from a common stock. The

ZOOLOGY.

56

chief causes of this divergence into varieties appear to be modi¬
fications of food and climate, and confining the breeds within
certain narrow limits. If these varieties of domestic animals
are allowed to return to their natural habits and condition of
life, the marked peculiarities disappear, and they assume again
their original type. It is probable that the same takes place
with regard to man ; that he has, for instance, in his constitu¬
tion the susceptibility of diverging into certain varieties, accor¬
ding as he is placed, in circumstances favourable to such a
change, and thus that climate, food, degrees of civilization,
and strict separation into tribes or colonies, may be the exter¬
nal circumstances which call forth the divergence from the
original type.

The chief distinction is the tint of the skin ; and climate
seems to be so intimately associated with this distinction, that
in the torrid zone we have the deep black tint, in the more
temperate regions a lighter bronze, and, as we pass onwards
to the higher latitudes, a still lighter shade, till we come to
the white skin and fair hair of the Dane and Norwegian.
Exceptions, however, occur. In some districts of Africa,
under the same latitude, the inhabitants of the mountains are
fairer than those in the plains, and the Esquimaux and wan¬
dering Tartar hordes have a dark skin, though living within
the Arctic circle.

A certain degree of civilization, too, seems associated with
colour. Thus all savages are dark skinned, and civilized
nations of a lighter hue. The females and higher classes of
the Turks and Hindoos are fairer skinned than the common
people.

100. There are three primary varieties of man, — the Cau¬
casian, or white ; the Mongolian, or yellow ; the Ethiopian, or
black. Some have added two others, — the American, or red
man, and the Malay, or olive complexioned.

101. The Caucasian is so called from Mount Caucasus and
the surrounding region having been the dwelling-place of the
primitive families after the Deluge. This variety is distin¬
guished by a fair skin, an oval face, and a well formed head ;
the features regular, and the nose and chin forming a nearly
perpendicular, or slightly bent line with the forehead.

The Circassians, Georgians, Arminians, Arabians, Jews,
Abyssinians, and probably Egyptians, belong to this variety.
Another branch includes the Indians, Persians, Pelasgians,
Scythians, from whence extended the Greeks, Romans,

MAN.

57

Germans, Celts, Spaniards, Hungarians, and other nations of
Europe. These have been distinguished as the great inventors
and cultivators of arts, sciences, and every accomplishment
conducive to the civilization of mankind.

102 The Mongolian variety is characterized by high cheek
bones, flat face, small eyes, placed obliquely in their sockets,
straight black hair, scanty beard, and yellow lemon-coloured
skin. The Altai mountains are supposed to have been the
original locality of this race ; and it includes the Chinese, a
very ancient nation, the Japanese, the Coreans, and islanders
of the Chinese Sea, and the hordes which extend to the east
of Siberia, including Russian Tartary. Though the Chinese
had attained a considerable degree of civilization at a very
remote period — beyond all historical record — yet they have
remained ever since in a stationary state, without attempting
any advancement. Their literature is circumscribed, and their
scientific acquirements of the lowest character.

The inhabitants of the Arctic regions, the Saraoiedes, the
Laplanders, and the Esquimaux, partake, in a considerable
degree, the characteristics of the Mongolian races, or they may
be a degeneration of the Caucasian.

103. The Ethiopian, or negro variety, is marked by a skin
of a deep black, the colouring matter residing in the mucous
net-work, as explained, sect. vii. 58. The hair is also quite black,
short, woolly, and crisped, or curled. The forehead is generally
rather small and retreating, the nose flat, and wide at the base,
the lips thick and large, the jaws elongated and projecting.
This is the general character ; but occasionally varieties are
found, with more regular and symmetrical features, with long
uncurled hair and lighter complexions. Africa, with its islands,
is the country of this race ; and savage barbarism has too
generally characterized the various hordes which wander ova-
its vast deserts.

104. The numerous islands of the South Pacific Ocean are
inhabited by different races, who have probably derived their
origin from all the three preceding. There are, in these
islands, at least two well marked races. The Malays, wit a
regular features, olive complexion, and dark, straight hair.
The Papuas, with negro features, and short curly hair. The
Malayan race are w’ell formed, quick, intelligent, and susceptible
of improvement, and more nearly resemble the Hindoos than
any others.

58

ZOOLOGY.

105. The American variety has regular features, not unfre-
quently the Roman nose, a retreating forehead, with high occiput,
long, straight hair, and skin of a red copper colour. They
consist of the aboriginal races of North and South America.
They are warlike, erratic, and possessed of many of the virtues,
and all the vices, of savages ; shew little disposition towards
civilization, and are rapidly decreasing in numbers. The
Chinooks are a tribe who flatten the foreheads of their infants
by artificial means.

The three marked varieties of mankind appear to have
originated at a very early period. In a painting found in one
of the ancient Egyptian tombs, there is an Egyptian sovereign
seated on his throne, giving an audience to ambassadors from
foreign nations, and among these are the white, the negro,
and the Mongolian features and colours, well defined and
represented.

106. As man appears in the two capacities of an animal and
intellectual being, and as he is instinctively, as well as artifi¬
cially, a gregarious animal, his most perfect condition must be
that of a state of civilization, where individual energies combine
for the general good, and where the moral and intellectual
faculties are brought into full activity.

In the repeopling of the earth after the Noachian deluge, the
seat of civilization appears to have been Babylonia and Chaldea ;
then it passed into Egypt ; and from this cradle of the arts and
sciences was knowledge disseminated to Greece and Rome,
and from thence westward throughout Europe. The fugitive
wanderers from the first centre of civilization would seem to
have carried ignorance and barbarity in their train, till at last
they terminated in the extreme islands of the South Pacific —
the Malayan, New Zealand, and New Holland territories. The
stream of intelligence has again changed its course, and now
the full current bears onward from the shores of Europe, dif¬
fusing itself over the habitable globe.

ORDER II. QUADRUMANA, Focr-Handbd.

107. The animals of this order are so called because their
upper and lower extremities are both furnished with hands.
In structure, they very closely resemble man, only they are
not adapted like him for the erect position ; the hand-like

ArES.

59

form of the lower extremities incapacitating them from walking
erect, except with great inconvenience, while the slender
muscles of the thigh do not afford that firm support to the
body which the erect position requires. The teeth are formed
like the human ; the head and face are also similar, although
there is a prolongation and projection of the jaws, which assi¬
milates them to brutes. The brain has three lobes ; but the
convolutions or furrows on its surface are less numerous than
those of man.

These animals live in trees, their four hands, which have
four fingers and a thumb, enabling them to climb from branch
to branch with facility. Many of them also are furnished with
tails, which are prehensile, the extremity of the tail winding
round branches of trees, and thus giving additional facilities of
movement. Their food consists of fruits, nuts, and roots of
plants. All the species are natives of tropical climates.
There are three divisions :

108. The Simia, or monkeys, with four incisor teeth, and
molars, with blunt tubercles ; the nails of the fingers fiat.

The Ouistitis, with oblique and pointed incisors ; nails
pointed and claw-like ; no cheek pouches.

The Lemurs, with sharp tuberculated teeth and incisors ;
the nail of the first hind finger pointed, the others fiat ; fur
woolly.

The Simia satyrus ( ourang-outang ) is the most remarkable
of this order. Its countenance and form, especially when
young, bear a close resemblance to the human. The body is
covered with a reddish hair, and the face is of a bluish tint.
It is a native of China, Borneo, and Malabar. Its gestures are
somewhat similar to those of man, and it imitates many of his
actions, is mild and gentle, but does not shew a sagacity supe¬
rior to that of the dog. It has a loud scream when irritated,
but has no powers of articulation.

The Troglodytes, or Chimpense, is another species, in
many respects similar, but covered with black hair. It is an
inhabitant of Guinea and Congo, lives in troops, and constructs
a hut of leaves and sticks, and arms itself with clubs and
stones when attacked by enemies. Some travellers estimate
its height as exceeding that of man ; but the individuals
hitherto brought to Europe are of stature inferior.

60

ZOOLOGY.

i

ORDER III. CARNARIA.

_09. This order includes various classes of animals, formed
with sharp teeth and claws, and who live either wholly or
partially on animal food. Their teeth are of three kinds, but
all more or less pointed, and the jaw has only one motion
upwards and downwards. The stomach is simple, and the
intestines of moderate length. This order contains several
sub-divisions.

110. Cheiroptera, or Bat family, is distinguished bv a
membrane stretched over their four feet, which enables them
to fly in the air. In other respects, they are quadrupeds, and
resemble somewhat the mouse. The arms and fingers are much
elongated, and on the thumb is a hook by which they suspend
themselves. Some species have short tails, and some long
ears. They live on flies, and are nocturnal, or pursue their
prey in the evening and during the night. In winter they
become torpid, and suspend themselves in caverns and dark
obscure places. They produce two young, and suckle them
There are numerous species. The vampire bat is of large
size, and pierces the skin, and feeds on the blood of animals.

The Lemurs are still larger, live in trees, and feed on
insects and birds.

111. Issectivora. This family is so called from feeding
on insects and worms. Many species lead a subterranean life.
The hedge hog, the tenric, the shrew, the musk-rat, the mole,
the scalops, belong to this division.

The hedge-liog is covered with sharp spines instead of
hairs ; and the skin of the back being ample, certain muscles
enable the animal to draw it over its head and feet, so as to
coil the body into the form of a round ball, with the prickles
opposed on all sides to an attacking enemy. This animal
lives on insects, and occasionally fruit, and lies dormant in its
burrow during winter.

The mole lives entirely under ground, and pursues its prey
by running along ruts which it constructs in the soil. For
this purpose, it is furnished with a projecting muscular muzzle,
and fore-legs formed like a hand, with powerful muscles
attached. With these it hollows out the soil, and at con¬
venient distances throws up the loose earth to the surface,

CARNIVORA.

61

forming mole-hills. One large hill contains the nest and
young of the animal, while from this centre proceed numerous
ruts in all directions. The mole has acute sense of hearing.
Its eyes are very small, and deeply sunk in its head. It is a
gluttonous animal, and cannot endure a long fast. The
slightest blow, especially on the head, kills it.

1 12. Carnivora. The true flesh-feeding animals have large
sharp pointed teeth, and their muscular bodies and sanguinary
propensities constitute them formidable animals of prey.
Almost all this family live exclusively on flesh : a few of the
weaker sorts, however, as some bears, live partly, if not
entirely, on roots and vegetables.

The Plantigrade, or those which place the whole sole of
the foot on the ground in walking, constitute a subdivision,
including, —

Ur sits — the bear. Metes — the badger.

Procyon — the racoon. Gulo — the glutton.

Nasua — the coatis. Ratclus — the rate!.

Of the bear, there are several species, as the brown, the
black, the labiated. They are large thick-limbed animals,
with a covering of grizzly hair. The black or American bear
hybernates, either excavating a hole in the earth, or lying
under the deep winter snows. At the commencement of their
winter sleep, they are plump and fat ; but this superfluous Cat
is gradually absorbed to supply them with nourishment.
Towards spring, they produce their young ; and at the period
of the melting of the snows, they crawl up from their lair
exhausted and feeble skeletons. The badger is also a hyber-
nating animal.

113. Digitigrade. These animals walk on the ends or tips
of their toes. To this division belong, —

Putorius— the polecats.
Mustela — the weasels, martins,
sable.

Mephitis— the skunk.

Lulra — the otter.

Canis— the dog, wolf, fox.
Viverra — the civet.
Genetta— genet.

Hyena — the hyena.

Felis— cat, li n, tiger.

The sable, a Siberian animal, is highly valued for its fur.
The skunk, when hotly pursued, emits a most insufferable
odour. The otter is an aquatic animal, and has webbed feet,
and a tail flattened horizontally. The dog tribe have the
mouth and nose prolonged, and the sense of smell highly

ZOOLOGY.

6*2

acute. They are also formed for swift running, and hunt
down their prey by speed of foot. They frequently also hunt
in company.

114. The dog ( canis familiaris ) is the most interesting and
the most sagacious of all the brute creation. Since the
earliest ages, he has been found the close and attached com¬
panion of man ; and such is his preference for human society,
that he will readily forsake that of his fellows to watch over
and accompany his master. His strength, his swiftness, and
his acute sense of smell, have rendered him a powerful ally to
man in his mastery over the other animals. The dog can
scarcely be said to exist as a wild animal ; for those which are
found in some countries at full liberty are most probably the
offspring of individuals once domesticated. As the dog is one
of those animals extremely prone to pass into varieties, it is
very difficult to say what has been the original of the nume¬
rous breeds now existing. Some have supposed the shepherd’s
dog and wolf dog the original type; or the Esquimaux or
New Holland dogs, which have straight and erect ears. The
natural food of the dog can be changed by domestication to
vegetable matter. The period of gestation is sixty days ; the
young are born with their eyelids closed, which open about
the twelfth day. They acquire their full growth in two
years ; and the extreme age is twenty years, the average
twelve to fifteen. The varieties are numerous, and by
training and breeding may be kept distinct ; but otherwise
they all ultimately lapse into a common type, a sure indication
that all are of one species.

The wolf so nearly resembles the larger dogs, that some
have supposed both animals to belong to one species. The
wolf was at a remote period an inhabitant of the whole north
of Europe. It was extirpated from North Britain about the
year 1577.

The hyena is an extremely fierce animal, is gregarious, and
lives in caves. It preys on dead bodies, and even robs the
human graves of their contents.

115. The feline tribe are distinguished by their short round
muzzle, their retractile claws, and their powerful muscular
apparatus in the fore-quarters, by which they are enabled to
take sudden and forcible leaps upon their prey. In the
greater number the pupil of the eye, instead of being round,
is of a linear form. The fore-paws are the organs by which
they beat down and seize their prey. These are padded

CARNIVORA.

63

Delow tlie toes by an elastic cartilaginous substance, to prevent
injury from their sudden and violent leaps upon the ground.
The retractile claw is also a curious contrivance to withdraw
the sharp point of the nail while the animal is walking, and
thus to preserve it unworn and pointed when it has occasion
to dart it out in seizing its victim. For this purpose the

claw is placed on the upper portion
of the last bone or phalanx of the
toe ; an elastic tendon or, keeps the
claw, under ordinary circumstances,
bent up ; the tendon b pulls it down¬
wards, while c, the retractile tendon,
draws it up again. The feline tribe do
not run down their prey by speed, but lie in wait for and
spring on it. Their habits are wary, cunning, and relentless.
They hunt by night, and are solitary and unsocial. The
greater proportion are inhabitants of tropical climates : the
lynx and common cat, however, range over the greater part of
the globe. Our domestic cats are probably derived both from
the wild cats of the country and from foreign species imported.
The wild cat is characterized by an obtusely pointed tail ; but
it is said the domestic cat assumes this form also when set at
liberty into its native haunts. The feline family may be thus
characterized •

A. of a uniform colour, without spots.

Felis Leo — the lion.

F. Concolor— the puma.

B. with transverse vertical spots.

F. Tigris— the tiger.

C with large circular spots.

F. On fa — the jaguar.

F. Pardus — .the panther.

F. Lcopardus — the leopard.

F. Jnbata— the guepard.

F. Uncia— the once.

D. with oblong spots and streaks ; tail
long.

F. Pardalit— the ocelot.

E. with streaks and variegated spots.

F. Serval — the serval.

F. Chati — the chati.

F. Tigrina — the margay.

F. Catus— the wild cat.

F. with tufted ears and short tail.

F- Caracal— the caracal.

F. Lynx— the lynx.

116. Amphibia. The animals of this family are so called
because they are aquatic. Their feet are short, and the toes
are united by membranes, which form paddles, by which they
swim with facility. The cellular membrane contains a large
quantity of fat, and their hairy covering is thick and short.
Of the phoca, or seal, there are several species. It is common
in the Northern Sea=, and is prized by the Esquimau as an

ZOOLOGY.

64

article of food. In our rivers, they are very destructive to
salmon.

The trichecus, morse, or sea-cow, is characterized by two
long tusks projecting from its upper jaw.

ORDER IV. MARSUPIALIA.

117. Marsupialia, or pouched animals, are so called, because
the loose skin of the abdomen forms a pouch which contains
their young. For the support of this pouch, there are two
bones projecting from the pelvis, which are peculiar to all this
order, and are found to exist in the males as well as the
females. The young are produced in an incomplete state,
and of small size, and are afterwards fully developed within
the pouch in which the nipples are situated. There are two
sub-divisions of this order ; one with sharp pointed teeth ani
digestive organs, and habits like the insectivora — the other
with teeth and stomachs adapted for an exclusively herbivorous
food. Both are peculiar to America and New Holland.

The Opossums ( didetphis ) are furnished with fifty teeth, a
greater number than that possessed by any other quadruped.
Incisors, ^ ; canine, ; molars, They have fingers and
an opposable thumb, but no nails. The tail is prehensile.
They live in trees, are nocturnal, and prey upon birds and
insects, and occasionally eat fruit. The Virginian opossum is
about the size of a cat, produces sixteen young at a birth, each
of which weighs only a grain. After birth, they are put into
the pouch, instinctively find the mammae, and in fifty days
acquire the size of a mouse. They now occasionally quit the
pouch, but continue to return to it till they become as large
as a rat. In some species the pouch is awanting.

The phalangista, or phalagers, belong to the second sub-divi¬
sion, and are characterized by their long pointed incisors, the
very small canini of the lower jaw, and the hind toes united
nearly to the points by a membrane. The flying phalagers
nave the skin extended from their flanks to the legs, which
enables them to bound through the air for a momentary space.
All these live on fruits.

The kanguroos have no canine teeth. The hind legs are
unusually large in proportion to the rest of the body, and their
mode of progression is by leaps or bounds. They are gentle
animals, entirely graminivorous. The gigantic kanguroo is six
feet in height. The flesh is esteemed as having the flavour of

RODENTIA.

65

venison. The young, at birth, are about the size of a mouse,
hut they increase rapidly in the maternal pouch, and remain
there even after they can graze, which they do by pushing out
their heads while the mother is feeding.

The phascolomys, or pouched rat or wombat, is in structure
similar to the next order, the rodentia. It is about the size
of a badger, and burrows like that animal.

ORDER V. RODENTIA.

1 18. The rodentia, or gnawers, are distinguished by the
chisel shape of their incisors, which the animals use in gnawing
or filing down their food. They are destitute of canine teeth,
and have molars with flat crowns.

The two incisors are covered with enamel
on the outer side, but have nono on the
inner ; the consequence of which is, that
the inner half is constantly worn down by
attrition, leaving the outer edge sharp as a
, chisel. As the tooth is subjected to constant wear, it as
constantly grows up from a curved socket, till at last it is
exhausted at the close of the animal’s natural period of life.
The lower jaw admits of only one motion, in a direction from
behind forwards. In general the hind part of the bodies of
animals of this order is larger and higher than the fore, so that
they leap instead of walk. Those species possessing strong
clavicles, as the squirrel, mouse, rat, use the fore legs as hands.
The eyes are placed laterally in the head, so that they see
both before and behind, as well as on each side. They are
mostly frugivorous or graminivorous. Some, however, feed
on flesh. Those genera with perfect clavicles are,

No. 18.

Sciurus — squirrel, flying squirrel.
Acotomys — marmot.

Myoxus — • dormouse.

Echimys — spring rat.

Mus — rat — mouse.

Cricetus — hamster.

Arvicula — field rat.

Fiber — musk rat.
Georychus — lemming.
Dipus— jerboa.

Ilelamys — jumping hare.
^pelax — rat mole.
Gcomys— Canada hamster.
Castor — beaver.

Those with imperfect clavicles are,

Hystrix — the porcupine.
Lepus — the hare.
Lagomys — rat hares.

E

Cavia — the guinea pig.
Chloromys — the agouti,
Ccclogenys — the pacas.

66

ZOOLOGY.

1 19. The harvest mouse is the smallest quadruped, its body
being about an inch in length.

The beaver is an aquatic animal. Its hind toes are webbed,
and its tail is horizontally flattened and covered with scales.
The industry of these animals in constructing dams across
rivers is well known. The object of this labour is to form a
sufficient depth of water, in order that they may construct their
houses, so as they may enter them by diving
under the water, and then ascend to the dry
station in the upper part. Where the rivers
are of sufficient depth, they do not form
dams, but construct their houses on the banks.

On the American rivers, the beavers ascend the stream from
their lodges in search of food. They make their excursions
under water, and have, at certain distances, excavations in the
bank, called washes, where they retire to breathe without
being seen. The hunters discover these places by the hollow
sound emitted when trod upon, and here they resort to take
the animals. The skin of the beaver is highly valued, an.
forms an article of extensive trade with the Indian hunters.

The rat hare of Siberia collects heaps of grass, and builds it
up like a hay rick, as a provision for the long winter. These
ricks are eagerly sought after by the Cossacks, as fodder for
their horses.

The musk rat secretes the highly odorous substance, from
whence it obtains its name, in certain glands beneath the tail.

The instincts and habits of the hare are very interesting,
especially the provisions and resources which nature has
bestowed on this extremely timid and defenceless creature, —
such as its congenial hue with the furze and stubble where it
couches, its projecting eyes, capable of taking a view of every
surrounding object, and ever on the watch, even in sleep ; its
extreme fleetness, its wiles when hotly pursued, and its choice
of situations according to the state of the weather.

The rat mole is a singular creature, with an angular head,
short legs, and no tail. Its deprivation of vision, too, is also
remarkable ; the eyeball is awanting, the rudiments of one, or
a small point only, being visible beneath the skin.

No. 19.

EDENTATA.

67

ORDER VL EDENTATA. Toothless.

120. All the animals of this order are deficient in the front
teeth, while some are entirely toothless. They have also
large hoof-like nails, and a slow and difficult progression
in consequence of the peculiar organization of their limbs and
chaws. There are three sub-divisions. 1. The tardigrada,
including the genus bradypus, or sloth, remarkable for its un¬
couth figure and sluggish motions. 2. The dasypus, including
the armadillos, which have a hard, scaley covering over their
bodies and tail, and live in burrows under ground ; the
orycteropus, or ground hog, and the ant-eaters, which are
toothless, and furnished with a long tongue. 3. The mono-
tremata, containing the echidna and ornithorynchus of New

These singular animals have the bill of
a duck, and their five toes united by a
membrane. There is in their skeleton a
breast bone, common to the two clavicles,
resembling the fourchette or merry thought
in birds. In the hind feet of the male
is a spur, with a cavity perforating it, through which flows a
fluid said to be poisonous. They are aquatic quadrupeds, and
covered with fur. It is yet unascertained whether they be
viviparous, or oviparous like birds.

ORDER VII. TACHYDERMATA. Thick-ikinned.

121. A thick, tough skin, and limbs either hoofed, or with
close toes, approaching to hoofs, characterize this order, of
which there are three sub-divisions.

122. Proboscidiana, with a flexible trunk or proboscis, five
toes to each foot, almost covered with callous skin — no canine
teeth, but two large tusks depending from the upper jaw. The
elephant is the only member of this family ; no less remarkable
for its gigantic size, than for its strength, agility, and docile
manners. The molar teeth are of enormous size, and flat.
When old and worn down, they are displaced by a succession
of new ones; but as the jaw could not contain both sets of
teeth, one below the other, as in other mammalia, the new
ones are formed behind the jaw, and advancing forwards,
gradually push the old ones out. Two or three supplies oi

Holland.

No. 20.

ZOOLOGY.

G8

molars are thus found curiously packed up in the posterior and
upper part of the jaw. The elephant lives on grass and leaves
of trees. It is said to live for one hundred years. The pro¬
boscis is curiously supplied with a multiplicity of muscles ; and
while it can tear up the largest tree of the forest, it can also
pick up the minutest object on the ground. The young
suck with the mouth, not with the proboscis. There are
two species now existing, although several more fossil species
must have lived at one time on the earth. The Asiatic
elephant has an oblong head, crown of the molars with trans¬
verse waving lines, exhibiting sections of the worn down
laminae, of which the tooth is composed ; ears comparatively
small ; four nails on the hind feet. The African species has
a round head, convex forehead, large ears, the crowns of the
molars divided into lozenges.

The molars of the extinct mastodon were more pointed or
nipple-shaped than the recent elephant, and the sections of the
points presented a lozenge shape.

No. 21.

Mast. don tooth.

No. 22.

Head of Hippopotamus.

123. Pachydermcita. Ordinaria have four, three, or two
toes, feet somewhat cleft, and digestive organs approaching to
the ruminantia.

The hippopotamus has a large naked body, short thick legs,
and an enormous head, with a muzzle which overlaps the
front teeth. These teeth are very remarkable ; the incisors
project in front horizontally, and the canines are large, curved,
and smoothed off obliquely at the point, so that they meet and
oppose each other like the blades of a pair of scissors. These
animals live in the rivers of Africa, and feed on succulent roots
and hurbs.

PACHYDERMATA. 69

The rhinoceros is another unwieldy animal, with three toes
on each foot, and a horn on the nose attached to the skin.

The tapir, the hog, the hyrax, belong to this division.
Numerous allied fossil animals have also been identified with
this family.

T24. Solipedes. A family with one solid toe or hoof, of
which the horse is the type, compose this subdivision.

The horse has six incisors in each jaw, and an empty space
between these and the grinders. The male, however, has
two small canini in the upper jaw. The incisors are impor¬
tant, as pointing out the age of the horse. The milk teeth
begin to grow about fifteen days after birth. At two years
and a half, the middle ones are replaced ; at three and a half,
the two next ones; and at four and a half, the outermost or
corner ones. All these teeth have originally an indented
crown, which they gradually lose by friction. When seven
or eight years old, this is entirely removed, and the horse is
no longer marked. The lower canini are produced at three
and a half ; the upper ones at four. They remain pointed till
six, a. id at ten they begin to peel off.

Th foot of the horse is divided into the hoof or horny part ;
the coronal bone to which this is attached, the pastern joint imme¬
diately above, and the cannon bone, which reaches to the knee.

The horse is the most useful of animals, possessing great
beauty and symmetry of form, and a disposition noble, gentle,
and affectionate, although impatient and resentful of rude
treatment. He is one of the few animals that cannot now be
found in his original state of nature, the wild horses of some
countries being the domesticated horse turned adrift into the
wilderness. Many varieties exist, differing in size, shape, and
other qualities. Temperate regions are best fitted for deve¬
loping his qualities. His natural food is dry grass. When
feeding in a wild state, sentinels are appointed to watch, and,
by snorting, to give notice of danger.

The horse has a large eye and a linear pupil : his vision at
night is very acute. By gentle and kind treatment, he may
tie trained to various purposes of usefulness, and is docile and
affectionate in the highest degree, though his instincts are not
very highly developed.

His training is usually associated with his feeding ; and in
this way his fears and disinclinations are overcome.

The other species of this family are, the dziggtai, the ass,
the zebra, and the quagga.

70

ZOOLOGY.

ORDER VIII. RUMINANTIA.

125. The animals of this order, after first swallowing their
food, bring it up a second time into the mouth, and re-chew
it : hence they are said to ruminate. They have four
stomachs.

No. 23. After half masticating

the newly cropped grass,
it is passed through the
gullet, a , into the first sto¬
mach or paunch, d. From
this it passes into the
second, c, the bonnet, or
honey-comb, the sides of which are cellular, like a piece oi
honey-comb. Here the food is moistened, and compressed
into little balls, which are successively taken up into the
mouth by a reversed action of the gullet, and re-chewed. After
minute mastication, the aliment is again swallowed ; but
instead of passing into the paunch, it slides through a groove or
canal, formed by two membranous sides of the third cavity, b,
(seen as a dark line in the cut.) This stomach is called the
inonyplies, or leaflet, from its laminar structure. From the
third stomach, b , the food next passes into the fourth, e, or
read. This is the true organ of digestion. The sides are
wrinkled, and here the glands lie which secrete the gastric
juice.

The foot of the ruminantia is divided into two halves or
hoofs. The molar teeth are flat, and the jaw has a rotatory
motion. In all the horned ruminantia, the upper incisors are
awanting, as well as the canine in both jaws. They are all
graminivorous, and their flesh is used as the food of man.
They are divided into those with horns, and those without.

12G. The camel has canine teeth in both jaws, two upper
pointed incisors and six lower, and from eighteen to twenty
molars. The toes are united nearly to the point. Attached
to the stomach is a cavity, containing numerous cells, which
forms a reservoir where the animal can retain water sufficient
to supply its wants for several weeks. On its back are two
humps, composed of soft muscular flesh and fat, which are sup¬
posed to be a provision for its sustenance, by means of absorp¬
tion, when deprived of food.

CETACEA.

The dromedary is another species, with one hump on its
back

The camel is only found in a domesticated state, and is a
most invaluable beast of burden, adapted by nature for the
arid countries in which it exists.

The lama is a South American camel, without humps, and
covered with a soft fur or wool much prized in manufactures.

The musk is characterized by two large canine teeth
depending from the upper jaw. They are of the size of the
goat, and light and elegantly formed.

127. The deer family have antlers, which grow from the
heads of the males. They are not horn, but true bone,
and are renewed every season, the old ones dropping off.

The, various species are the stag, the moose deer, the rein
deer, the fallow deer, Virginia deer, axis, roebuck, &c.

The giraffe, or camelopard, has two small conical horns,
which are permanent, and a small tubercle or third horn
between. The extreme length of its neck and forelegs renders
it a very remarkable animal.

128. The ruminantia with hollow horns have two promi¬
nences of bone attached to the skull called moulds, on which
the true horns gradually grow, increasing, by successive rings,
every year of the animal’s life. This horny albuminous matter
is identically the same substance as the nails, claws, and hair.
I11 horns, we perceive the fibrous structure of their formation,
and the rings or undulations point out the successive annual
growth. The horned ruminants have neither canine teeth nor
incisors in the lower jaw. The form of the lips and mouth,
however, is admirably suited for seizing and cropping the
herbage on which they feed. In the fields they browse their
food hurriedly, und then retire to thickets and places of shelter
to ruminate. They are gregarious, generally swift-footed, and
readily perceive the approach of enemies by their acute sense
of smell. The genera are, —

Aniilopus, — Antilope and gazelle.
Capra,— the goat.

Ovis,— the sheep.

' Common ox.
) Auroch.

B°s j Buffalo or bigon.
v Musk ox.

ORDER IX. CETACEA.

129. The cetacea, or whale tribe, although aquatic animals,
and externally formed like fishes, belong to the mammalia.

ZOOLOGY.

72

They have warm blood, breathe by means of lungs, and suckle
their young. They have no hind feet, but the body terminates
in a horizontal tail. Their anterior extremities are short, and
formed into fins.

The herbivorous cetacea have teeth, with flat crowns, and
live on vegetables. They consist of

Manatus — Lamantine or sea cow.

Halicorus — dugong or siren.

SUUenis — stelleri.

130. The ordinary cetacea are furnished with a blow-hoie
communicating with the mouth and nostrils, and opening at
the top of the head, through which they discharge the super¬
fluous water taken into their mouth along with their food ;
and by means of which they can inhale atmospheric air, simply
by raising their head a few’ inches above water, without the
inconvenience of depressing their large bodies, and raising
their mouth and nostrils at every inspiration. The body is
covered with a smooth skin, without hair, and below’ is a thick
layeT of blubber or fat, which serves to give buoyancy to their
huge forms, and also to protect them from the cold of an arctic
sea. The stomach is divided into five or seven sacks, and
they have several small globular spleens. They have two
anterior paddles, and a large tail ; some species have a dorsal
fin composed of tendinous substance ; some have round flat
teeth, while others are toothless.

The dolphins ( ddphinus ) have teeth in both jaw’s, and a
long muzzle. They are the most carnivorous of the family.

The porpoise, or hog fish, has a short convex muzzle.

The narwhal, or sea unicorn, has a projecting spiral tooth,
from seven to ten feet long. A second tooth remains unde¬
veloped in the jaw.

The cachalots have an immensely enlarged head, or rather
face and jaw’s. The upper jaw’ is toothless, but the under
contains a row of conical teeth, which enter into corresponding
cavities of the upper jaw.

BIRDS.

73

The baleen a mysticetus , or
common whale, has a large some¬
what elongated mouth. The
jaws contain no teeth, but are
furnished on each side with
laminae of whalebone, which
serve to retain the minute me¬
dusae on which the animal feeds.
The oritice of the gullet is ex¬
tremely small compared to the
mouth and size of the animal.

The whale exceeds in size any other animal, being, on an
average, seventy feet in length. Floating in the dense element
of water, this huge mass, weighing upwards of one hundred
and sixty thousand pounds, which would be unwieldy on land,
is possessed of considerable agility, and has prodigious muscular
power, especially in the tail.

The whale is valued for its blubber, from which oil is pro¬
cured ; and for the elastic horny substance of the jaw, called
whalebone.

No. 24.

SECTION XIII.

CLASS II.— AYES, BIRDS.

131. Birds form the second class of the vertebrata, and are
distinguished from the mammalia by their oviparous birth, the
young being hatched from eggs.

They are also, with one or two exceptions, adapted for
flight ; and, accordingly, we find arrangements in their
skeleton and other parts of their bodies, for this purpose.

They are bipeds, and stand in a semi-erect position, their
bodies hanging forwards. The upper extremities are formed
into wings, and they use their mouth and bill for picking up
their food.

132. The neck is long, and contains numerous vertebrae,
while the pelvis is very much extended, to admit of the many
strong muscles which are attached to the thighs, for the
support of the body. The sternum, or breast bone, is also
large, and is divided in the middle by a keel, on each side of
which is a hollow, where lie the thick and powerful muscles
that move the wings. The junction of the two clavicles forms
the fourchette, ( merry thought,') which keeps the shoulders

74

ZOOLOGY.

apart in the rapid motions of the wings. The last bone
of the wing corresponding to the hand and toes of the
mammalia, has one finger, and the rudiments of two more.
These serve to give attachments to the spurious quills of the
wing. The tail bone is short, and affords attachment to from
twelve to fourteen quill feathers. The ribs are strengthened
and supported by transverse portions of bone, which unite about
tfieir middle. The leg consists of the femur, or thighbone,
and the tibia and fibula : these are connected at the carpus by
a spring-joint, which keeps the leg extended without any
muscular exertion on the part of the animal. The foot con¬
tains one bone, which terminates in three pulleys. The
toes are generally three, with an opposing toe behind.

133. 1 nere is a beautiful muscular contrivance in the leg,
especially of those birds that perch on trees, for keeping the
claws fixed to the branch, without an effort of the animal. For
this purpose, a set of muscles take their origin in the pelvis, and
their tendons passing along the thigh, cross obliquely the knee-
joint, bend under the heel, and are inserted into the inferior
part of the toes. Thus, the mere weight of the animal’s body,
when it goes to rest, by bending the joints of the thigh and
leg, puts the tendons on the stretch, and forcibly draw’s the
claw’s around the perch. In this position, the bird sleeps in
safety amid the rocking of the boughs in the highest gales.

To increase the weight, and consequently the tension of
the tendons, some birds sleep with one foot drawm up, while
others grasp a stone in it. The common practice, too, of
sleeping with the head under the wring, brings the centre of
gravity more within the line of the legs and feet.

134. Birds are covered with dow’n and feathers of an
extremely light texture, and of a nature to protect their
bodies from the atmospheric changes to which their flights
expose them. The feathers are attached to the skin by a
hollow’ quill filled with air, and which at first contained the
nutritive vessels from w'hence the plume wras developed. The
numerous lateral fibres of the quill-feathers are ingeniously
hooked together by their serrated edges — a contrivance which
admits of their compactness being easily restored, although
ruffled and separated by the rapid motion to which they are
continually subjected. The surface of the feathers, especially
in aquatic birds, is kept waterproof by an oil secreted in
glands near the tail, and which is regularly smeared over them
by the bird using its bill for this purpose.

BIRDS.

75

135. The lungs of birds are placed close to their ribs — they
are undivided, and are enveloped by a membrane pierced with
holes, through which a quantity of the inspired air is forced
into various sacs and cavities of the chest and abdomen, and
also into the interior hollows of the bones, to add to the
buoyancy of the body.

The respiratory and circulating organs are vigorous, and
the animal heat is greater than that of the mammalia.

Birds have no teeth — their mandibles are prolongations of
the maxillary bones, and are covered to a certain extent with
a horny bill, varying in size and hardness.

136. The digestive apparatus consists of three parts, a dila¬
tation of the oesophagus, called the crop ; a membranous
ventricular sac which pours out a fluid analogous to saliva,
by which the food is moistened, and rendered soft and pulpy ;
and the gizzard, or true stomach, composed of thick and
powerful muscles, and lined internally with a cartilaginous
villous coat. Here, especially in granivorous birds, are found
a number of sharp-edged pebbles, which the animal swallows,
and which assist in the trituration of the food, preparatory to
its solution in the gastric juice. In carnivorous birds, the
stomach is more simple, approaching to the single sac of the
llesh-feeding mammalia.

137- The brain of birds is large in proportion to the body,
especially the cerebrum, which, however, contains no convo¬
lutions.

The sense of sight is very perfect in birds, and is adapted
both to near and distant vision, by certain changes of the
convexity of the eyeball, and position of the lens. The
inarsupium, a muscle attached to the posterior chamber of the
eye, is supposed to be conducive to this arrangement. Birds
have a third eyelid, called the tnembrana nichtans , which, at
the same time that it protects the eye in the rapid flights of
the animal, permits of a certain degree of vision. The hearing
of birds is also acute — although, in general, there is no external
ear, but merely an orifice. In nocturnal birds of prey, as the
ow’l, the external ear is of great size.

The orifices of the nose are placed at the base of the bill.
The acute sense of smell of the vulture and other birds is
disputed ; and they probably depend more on their powers of
sight in singling out their prey.

The tongue of most birds contains little soft flesh, and is
composed chiefly of cartilage and bone. The sense of taste

76

ZOOLOGY.

seems not to be very great. Neither can touch be very
exquisite, as every part of their body is covered with sub¬
stances ill adapted for conveying sensitive impressions.

13S. The trachtea, or wind-pipe, consists of entire circular
rings. At its lower part, where it branches into two, is
placed an epiglottis or elastic flap, by which sounds are pro¬
duced, and where emanate the notes of song birds. The
large proportion of air inhaled, and the powerful muscles of
the chest, enable those little animals to pour forth an amazing
volume of sound, the modulations of which are, in some cases,
so exquisite.

139. The shape of birds is admirably suited for quick move¬
ments through the resisting air. Thus the body tapers at both
ends, and swells out gently in the middle. The feathers of
both wings are also equally adjusted, so that their actions
exactly coincide ; the wing is concave above and convex below,
thus presenting a rounded and slightly resisting surface in its
elevation, and a strong resisting surface in its depression.
By modifying the quantity of air thrown into their bodies,
'niids can also soar high into the atmosphere, or skim the

rface of the earth. The eagle, the falcon, the kite, and
many others, after ascending to a great height, become so
buoyant from the expansion of the air contained in their
cavities, that they soar and float along almost without the
efforts of their wings. When they wish to descend rapidly,
they suddenly expel the superfluous air, and thus render their
bodies heavier.

Most birds renew their feathers twice a-year, which is
termed moulting. At these periods, they are sickly. Some
assume a different colour of plumage in summer from that of
winter, as the ptarmigan ; and, in general, the colour of birds
varies according to their age.

The ingenuity and perseverance displayed by these animals
in constructing their nests, and the all-absorbing interest
which the care of their young excites in them, are not the
least interesting portion of the history of the feathered tribe.
If, to this, we add the beauty and variety of their plumage,
their wheeling flights through the air, and their melody asso¬
ciated with every thing that is lovely in nature, and cheering
in the season of the year, we need not be surprised that they
should so frequently engross the fondest speculations of the
lover of nature.

140. Possessed of such powers of locomotion, the migrations

BIRDS*

77

of birds are more frequent and more extensive than that of
most other animals. There are two kinds of this migration.
The one of birds that spend the summer in our temperate
climates, and leave us on the approach of winter — such as the
swallows, the cuckoo, quails, &c. ; and the other of those that
leave the arctic climates at the close of the year, and come to
spend a milder winter on our insular shores. Of this kind are,
the swan, goose, dotterel, &c. More partial migrations take
place from one part of a country to the other,, at particular
seasons, and among particular classes of the feathered tribes.

In these migrations, the birds take advantage of land as
much as possible, and skim along the coasts, or cross the
inland countries, resting when they become exhausted. As
birds fly at the rate of from fifty to a hundred miles an hour, the
crossing of a sea, or a considerable space of ocean, especially to
those that have amazing strength and endurance of flight, is
not deemed an arduous undertaking.

After all, such migrations seldom extend across a wide space
of ocean. No American birds come to this country, or Europe,
except in rare instances, when stragglers are forced out to sea
by hurricanes. The male birds are said to fake the lead in
their migratory flights, and to arrive a day or two before the
females. The great sympathy which birds manifest with
atmospheric changes — the presence or absence of the food
on which they live — and a certain unknown internal change,
in some cases exhibiting symptoms of increased heat and
irritation in their systems, seem all conducive to excite the
particular instinct which impels to emigration.

There is a Power, whose care

Teaches thy way along that pathless coast,

The desert and illimitable air.

Lone wandering, but not lost.

All day thy wings have fann’d,

At that far height, the cold dim atmosphere,

Yet stoop not weary to the welcome land,

Though the dark night is near.

In describing birds, it is necessary to be acquainted with the
following terms :

78 ZOOLOGY.

No. 25.

a tlie cere, a naked piece
of skin at the base of the
bill in several species of
birds ; b the wing coverts
or tectrices ; c the tertials
of the wing, attached to
the second bone ; d the
secondaries ; e the prima¬
ries attached to the first
bone or carpus ;/the rump
feathers ; g the middle tail
feathers. The other terms
are, the occiput or back of
the head — the gorge or
throat — the ventre or belly.

The nests of birds are interesting objects, and vary in
structure according to the species. The eggs also are of
different hues and shapes, according to the families to which
they belong. In many instances, the colour of the egg is
adapted to the surrounding objects among which the nest of
the bird is situated. The development of the chick in the egg
has been explained sect. vi. 48.

141. The form of the bill, and feet and claws, afford the
distinctive marks of classification. Temminck arranges birds
into sixteen orders.

ORDER I. RAP ACES, BIRDS OP PREY.

142. These are distinguished by their strong, hard, and
booked beaks and talons, large wings, muscular bodies, and
acute vision. They have four toes on the foot, and a mem¬
brane or cere at the base of the upper mandible. They prey
upon other birds and small animals, and are strictly carnivo¬
rous. They are divided into diurnal, or those that prey
during the day, and nocturnal or night feeding. The diurnal
comprehends the vultures, condor, eagles, and the hawk
family. The nocturnal, the owls, of which there are several
species.

The golden eagle is, like the lion among quadrupeds, the
king of birds, and this distinction fie merits from his size,
muscular form, noble and daring aspect, and his prowess as a
hunter. These birds, like carnivorous quadrupeds, are soli¬
tary. comparatively scarce, bring forth only two young, and
build their nests in high and inaccessible rocks and moun¬
tains.

The owl exhibits a structure admirably suited for its

a

BIRDS.

79

nocturnal habits. Its soft silken plumage enables it to tiit
through the dusk with a noiseless motion — its eye is, like the
cats, adapted for nocturnal vision — and it3 external ear is most
ample, and calculated to take in the slightest sound which the
birds or mice, on which it preys, may convey to it.

ORDER II. OMNIVORES.

143. Embraces those birds which live on all kinds of food.
The beak is robust, of middle size, and sharp on the edges ;
the upper mandible convex, and notched at the point ; feet
with four toes ; wings of medium length ; quill-feathers termi¬
nating in a point. Among this order are ranged, —

Corvus— the raven, hooded-crow, Garrulus— magpie, jay.

rook, daw. Oriolus — the golden oriole.

Sturnus — the starling. Paradisca — birds of paradise.

The crow is remarkable, as being one of the few animals
which are found in every climate, and almost every region of
the globe. It feeds chiefly on worms and insects ; and hence
is supposed to do less harm to the fields of the farmer, than
the benefit that it bestows, by ridding the ground of vermin.
A rookery is an interesting scene, where the instinctive sagaci¬
ties of the crow are amusingly developed.

ORDER III. IN3ECTIV0RE3.

144. The bill is short, or of a middle size, straight, rounded,
or curved. Upper mandible curved, and notched at the tip ;
base for the most part beset with bristly hairs ; feet with three
toes before, and one behind, with parallel articulations, the
exterior toe adhering at its base ; or, in some species, to the
first phalanx of the middle toe. This order includes many
song birds. They live chiefly on insects in summer, and on
berries and seeds in winter. The principal genera are, —

Turdus— thrush, blackbird,

Lanius — shrike.

Muscicapa — fly-catcher.
MotaciUa — wagtail.

Sylvia — warblers, red-breast

mocking bird, ouzel.

Troglodytes — wren .

Edolius — malabar edolius.
Saxicola — chat, wheat -ear.

ORDER IV. GRANIVORES

145. The bill more or les3 conical ; short, strong mandibles,

80

ZOOLOGY.

mostly without notches ; wings of medium length ; four toes,
the anterior ones entirely divided ; feed on seeds of plants and
grain.

Alauda — lark
Parus — titmouse
Emberiza — bunting
Loxia — crossbill

The bullfinch is celebrated for its musical powers, and the
facility with which it may be taught to sing airs. The cross¬
bill has a singular bill ; the points of the mandibles crossing
each other, from whence it derives its name.

Pyrrhula — bullfinch
Fringilla — finch
Colias — coly
Tanager — black tanager

ORDER V. Z Y GODACTYLI.

146. The form of the bill varies, is more or less curved,
sometimes hooked or straight, and angular. The feet have
two toes before, and two behind. Among the genera are,

Cuculus — cuckoo Psittacus — parrot, cockatoo

Ramphastos — toucan Pic us — woodpecker

Trojcn — quizel Yitnx — wry-neek

ORDER VI. CANISODACTYLI.

147. Bill more or less bent, or straight ; slender feet, with
three toes before, and one behind, the exterior one always
adhering at its base to the middle toe ; the hind toe usually
long ; all the toes with long bent claws. Includes

Ojcyrh gnchus Certhia — creeper

Stitt a — nut-liatcli TicJiodroma — wall-creeper

TrochUus — humming bird Upupa — hoopoe

The humming birds are the smallest and most brilliant in
their plumage of all the feathered tribes. They are natives of
America.

ORDER VII. ALCYONES.

148. Bill of medium size, long in some species, pointed, and
nearly quadrangular, either straight or bent ; tarsus very short ;
three toes before, adhering, and one behind. Including

Merops — bee-cater
Dacelo — gigantic dacelo

Akcdo — king-fisher

BIRDS.

81

ORDEB Tin. CHELIDONES.

149. Bill very short, greatly depressed, and much dilated at
the base ; the upper mandible curved at the point ; legs short ;
three toes before, and one behind ; front toes free, or connected
at the base by a short membrane ; claws much hooked ; wings
long. Including

Hirundo — swallow, swift, martin
Caprimulgus — goatsucker
Podargus — horned podargus

ORDER IX. COLUMB.&

150. Bill of medium size, compressed ; the base of the upper
mandible covered by a soft skin, in which the nostrils are
situated, the point more or less bent ; feet with three com¬
pletely divided toes before, and one behind. Containing the
family of pigeons, remarkable for their symmetry of form,
great capability of domestication, and power of sustaining long
and rapid flights. Pigeons feed their young by discharging
from their crop the softened grain and pulse which they collect
there. The rock pigeon is supposed to be the original of our
European varieties.

ORDER X. GALLINjE

151. Bill strong; short, convex, and in some genera it is
partly covered by a cere ; upper mandible bending from its
base, or only towards the tip, and projecting over the point of
the lower one ; nostrils protected by a cartilaginous scale,
naked in some, and feathered in others ; wings short and con¬
cave ; feet with three toes before, and one behind, united at
the base by a membrane. Includes

GaRus — domestic cock Kumida — guinea-fowl

Phasanius — pheasant Tetrao — grouse

i Icleagrus — turkey Perdix — quail, partridge

The domestic fowl, and the pheasant, are supposed to have
come originally from Asia. The turkey is a native of America.
The ptarmigan, or white grouse, is an Alpine bird, and changes
the colour of its plumage on the approach of winter.

F

■a -2

ZOOLOGY.

ORDER XI. ALECT0RIDE8.

152. Bill the size of the head, or a little shorter, strong and
robust ; the upper mandible convex, and frequently hooked at
the point *, the toes slender, three before and one behind, the
articulation of the hind toe higher than those before. The
genera are, —

Psophia — ■ trumpeter Palemedea — screamer

Dicholophus — crested dicholophus Channa — jacana
Glariola — collared pratincole

ORDER XIi. CURSORE3.

153. This order is characterized by a bill of medium size or
short, long legs and naked above the knee, with two or three
anterior toes only. It includes some remarkable genera, as

Struthio — ostrich Otis — bustard

Dromaius — emu Cursorius — courier

Casuanus — cassowary

The ostrich, cf which there are two species, the African
anu American, is the largest and most powerful of birds. The
African ostrich is six to eight feet high. It is not adapted for
flight, and therefore has the legs more muscular than the
wings ; and the body is covered with plumes of detached
filaments, instead of the compacted feathers of other birds.
The third, or inner toe, is so small and imperfect, as to have
been overlooked by many observers. It runs with great swift¬
ness, assisted by its wings. When hotly pursued, it is said
to dash stones behind it with great violence. It lays its
eggs on the sea sand, and leaves them to be hatched by the
warmth of the sun. These eggs weigh nearly three pounds
each. In colder temperatures, the same bird, however, sits on
and hatches its eggs with the utmost assiduity. It feeds on
grass and grain ; and so powerful is its large gizzard, that it
wears down and obliterates the stamp of coins that it may
have swallowed. The American species is smaller, and of a
grayish yellow colour.

The emu is seven feet high ; colour of plumage brown, of
different shades, consisting of pendulous plumes of a hairy
texture. It ts a native of New Holland.

• • 4

BIRDS.

83

ORDER Xm. GRALLAT0RE3.

154. The birds of this order, from their habits, are called
waders. The bill varies — is generally straight, elongated,
conical, compressed, and rarely depressed. The legs are long
and slender, and for the most part naked above the knee.
Three or four toes. The genera are numerous, and are sub¬
divided into groups. Among these are, —

Charadrius — plovers Scolopax — woodcock

Grits — cranes Hall us — rails

ORDER XIV. PINNATIPEDES.

155. Bill of medium size ; legs of moderate length ; the
toes with half or rudimentary webs along their sides. The
species living much in the water.

Fulica — coot Podiceps — grebe

ORDER XV. PALMIPEDES.

156. Bills varied in form, some round, others flat, legs
short, and placed far behind, anterior toes, wholly or partially
connected by a membrane, hence the terra web-footed. The
species are all aquatic ; and the families are numerous.

Larus — gulls
Procellaria — petrels
Diomedea —albatross
Anser — goose

Cygnus — swans
Anas — ducks
Colymbus — divers
Mormon — puffins.

Many birds of this order are migratory ; spending their
summers, and breeding in the arctic regions, and coming to
more temperate climates during winter. They live on fish
and marine animals.

ORDER XVI. INERTES.

257. Characterized by sfcort, thick, inactive bodies ; legs
placed far behind ; toes short ; wings not fitted for flight.
The apterex inhabits New Zealand. Didus, the dodo, within
the last two hundred years, was found in the Mauritius, but is
now extinct.

84

ZOOLOGY.

SECTION XIV.

CLASS III. — REPTILIA, REPTILE*.

158. In the class of reptiles, vve begin to perceive a falling
off from that complete organization and vigorous play of the
vital functions, which are found in the preceding classes.
This is remarkable in the less hard or compact structure of
the bones, and the deficiency of portions of the skeleton ; in
the feeble power of producing animal heat, arising from an
imperfect aeration of the blood ; in their sluggish motions ;
diminished power of excitability, and the obtuseness of the
organs of sense. %

The skin of reptiles is either naked, or covered with scales ;
and among some tribes it is periodically thrown off and
lenewed. They are cold, red blooded animals, respire by
lungs, and some also by branchiae. Some are without feet,
others have two, and four. Certain species live on land,
others are aquatic. The structure of the heart, and the cir¬
culation, is peculiar. The whole blood does not regularly
pass through the lungs, a part of the venous blood flowing by
a direct communication from the great veins to the vessels
of the left side of the heart. Respiration is also frequently
interrupted for a considerable period without injury to the life
of the animal. The heart is either single or double. The
lobes of the lungs are unequal, and the cells larger than in the
higher classes of animais.

In consequence of this imperfect respiration, the animal heat
is kept low, the temperature rising very little above that of
the surrounding medium, the whole animal energies also
partake of this diminished activity — their motions are slow,
their appetites irregular, their absorbent and exhalent systems
inactive, and so powerless are they in resisting cold, that in
diminished temperatures they fall into a state of torpidity, and
may be frozen with a cold which congeals water.

The brain is small, and the manifestations of instinct very
incomplete. The living actions are frequently carried on after
decapitation ; such as pulsation of the heart, and muscular
motion, circumstances that indicate the influence of the nerves
and ganglions on the vital functions. The senses of reptiles
ure five, but they are obtuse, and in some cases very imperfect.
The hard horny plates, or the tough skins with which they

BIRDS.

85

are covered, prevent a delicate sense of touch. The ear is
simple in its structure, and not very sensitive to impressions of
sound ; and the eyes are frequently covered by a semi pellucid
membrane.

Reptiles are oviparous, either producing spawn, which
becomes vivified without the hatching or care of the parent,
or they are ovo-viviparous, producing eggs containing living
young. In the frog, and some others, the young undergo suc¬
cessive metamorphoses in their embryo state. (See Sect.
vi^48.)

This class has been divided into four orders.

ORDER I. CHELONIA, TORTOISES.

No. 26.

159. The heart has two auricles, and the body is incased
in a horny buckler, or double shell, composed of plates called
tortoise shell.

Although the external appearance of these
animals would not indicate any resemblance
to the vertebrata, yet, on examining them
internally, we find a bony skeleton with a
vertebral column, though somewhat imper¬
fect, and four extremities exactly similar in
structure to those of the higher vertebrata.

Tortoises have no teeth. The cavity of
the chest not permitting of alternate eleva¬
tion and depression, they respire by an
effort of the mouth and nostrils alone.
Through the latter they inspire air ; and placing the tongue
over the inner cavity of the nostrils, so as to shut it, they
force the air down into the lungs. Some live on vegetable
matter, others on insects and fishes, but they can remain
months, and even years, without eating. They are said to
live, at least, a century. Tortoises are divided into land, fresh
water, and marine. The turtle is esteemed for the richness of
its flesh. It is from six to seven feet in length, and weighs
from seven to eight hundred pounds. It is gregarious, and
feeds on sea-weed, and lays its eggs on the shore among
sand.

ORDER II. SAURIA.

159. The heart has two auricles. The body is covered
with scales, and there are three or four feet. The lungs are

ZOOLOGY.

86

large, and extend along the back. The mouth is armed with
teeth, and the toes with claws. The tail is long, and often
thick at the base.

Geckotida — geco.
Cammceleonida — chameleon.
Scincoide — elongated lizard.

Crocodilia — crocodile.
Lacertinidia — lizards.
Iguanada — iguana, draco.

The crocodiles, of which there are two kinds, the gavial and
alligator, are aquatic animals, thirty feet long. The young are
produced from eggs, which, notwithstanding the size of the
animal, are not larger than those of a goose.

The chameleon (little lion) lives in trees, and feeds on
insects. It has several curious adaptations for its mode of
life. Its toes are admirably formed for grasping the branches
— its tail is prehensile — its eyes project from the sockets, and,
incased in a tube, can be moved in all directions without
motion of the head. The colour of the skin is susceptible of
three or four shades, yellow, green, and purple, suiting it to
the tints of the leaves ; and the tongue, which equals in length
its body, has such elasticity as to be compressed into half an
inch, and suddenly extended to six or seven inches. Its tip is
hollow, and covered with a viscid fluid, for entangling flies.
The lungs are of enormous proportions to its body. The change
of hue seems to be influenced greatly by the quantity of light —
by the respiration, and the passions, and desires of the animal.
Its locomotion is extremely sluggish.

ORDER III. OPHIDIA.

160. Serpents have elongated bodies — without feet — a heart
with two auricles — some with one lung — a scaly covering, or
naked skin. The skeleton consists of a vertebral column,
and ribs — sometimes the rudiments of feet are visible. Among
the families are, —

Coluber.
Crotodus.
Viper a.
Xuda.

Anguina.

Amphisbcena.

Typhlops.

Boa.

Serpents are either innocuous, or furnished with a poisonous
apparatus.

BIRDS.

87

No. 27.

The venomous serpents, as the
coluber, rattle-snake, vipers, have a
bag in the upper jaw, which contains a
poisonous fluid. When a wound is
made by a bite of the animal, this
fluid passes by a duct along a groove
in the tooth, and thus is instilled into

its victim. They have a slender forked tongue.

The motion of serpents is of a waving nature, produced by
the successive actions of the muscles on their jointed
body. Some live in water, others on the ground, and a few
in trees. Their eggs are generally connected together.

The boa is above thirty feet in length. Its jaws are
of great capacity, and it bruises its prey into an elongated
flattened form before swallowing it, smearing it over with
saliva. The rattlesnake has a horny jointed appendage to its
tail, by which it makes the peculiar noise, from whence its
name is derived.

ORDER IT. BATRACHIA.

161. The frog tribe have a single heart, two lungs, and in
their embryo state branchiae, which, in some species, as the
siren, are retained through life. They have four or two feet,
with webbed toes, and a skin without scales. The genera con¬
sists of, —

liana — frogs.
Scdamandra.

Proteus.

Siren.

The males of the green frog croak very loud, and, in doing
so, expand two large bladders placed at the angles of the
mouth.

The ova of the pipa or Guinea frog are hatched on the back
of the female, where they grow into tadpoles, and remain there
for three months, till they have acquired four legs.

The tree frog of America adheres to the leaves and branches
of trees, by a slimey matter which covers its skin.

The toad is a loathsome-looking animal, but is not poisonous.
It is very retentive of life ; and instances are adduced of its
living entombed in hollows of stones and trees for centuries.

83

ZOOLOGY.

SECTION XV.

CLASS IV. — PISCES, FISHES.

162. Fishes form the fourth and last class of vertebrated
animals. The bones are less compact even than those of
reptiles, and have a fibrous structure. The vertebrae are
circular, with hollow cavities on both ends, instead of the
alternate concave and convex surfaces, by which those of the
higher vertebrata are jointed. These circular vertebrae are
connected by an elastic cartilaginous substance, which admits
of a vibrating motion horizontally. The processes of the
vertebrae expand into ribs, having a groove on each side,
along which the nerves and ganglions pass.

The head is composed of numerous bones, imperfectly
connected together by cartilage and ligaments. The fins are
in place of limbs, and are supported by small bones, corres¬
ponding to the tarsal bones of the higher animals.

163. The heart of fishes is single, consisting of one auricle,
and one ventricle. The blood is propelled from this ventricle
to the vessels of the branchiae or gills, situated on each side of
the head. Over these gills, the water taken in by the mouth,
in a manner analogous to respiration, constantly passes ; and
after imparting a quantity of oxygen gas contained in it to the
blood, escapes through an opening covered by a flap, called
the operculum. The venous blood having thus received a
quantity of air, is conveyed into a vessel, corresponding to
the aorta, by which it is circulated throughout the body.

The covering of the gills is called the operculum, and is
divided into three parts ; in some orders of fishes, the opercu¬
lum is absent, and the external communication is by several
circular openings.

The scapular bones, and the pelvis, are very imperfect in
fishes, are unattached to the rest of the skeleton, and vary in
their positions.

Fishes are cold blooded, their respiratory functions being no
more than adequate to keep their temperature a little above
that of the surrounding medium.

FISHES.

89

No. 28.

a operculum, or gill cover, b pectoral fin. c ventral.
d anal and caudaL e dorsal.

164. The shape and entire structure of fishes are adapted
for the medium in which they live. The body tapers towards
the head and tail, and swells out in the middle. The fins and
tail are the organs of motion. These fins are composed of
membrane, supported by rays. The spinous rays are com¬
posed of a single piece, hard, flexible, pointed ; the articulated,
or branched rays, are made up of joints or branches articulated
together. The number of fins vary in the different classes ;
there are generally four, sometimes two ; and, in some cases,
none. They are named from their positions, as explained in
the wood cut.

Besides the skin, there is a covering of scales in a great
proportion of fishes, and these vary in form, according to the
different orders.

Along the body of the fish, on each side, there is a line of
peculiar scales, in many cases forming a dark band, as in the
haddock. In these there are glands which secrete a tenacious
mucus, with which the surface of the body is kept constantly
lubricated, and thus the macerating effect of water is prevented.
There are cirri, or long tapering bodies, which spring from
some fishes, that seem to act as organs of touch.

165. The brain of fishes is small, and does not fill the entire
cavity of the cranium. (Sect. viii. 63.) The different parts of
the brain are arranged one after the other. At the base of the
olfactory nerves, are ganglionic knots. The nostrils open by
two simple cavities at the end of the muzzle.

The cornea of the eye is very flat, to adapt it to the dense
medium of water ; and there is little aqueous humour. The
lens is almost spherical, and made up of innumerable compact
layers of albumen. The tongue and palates of fishes can have
but little sensibility of taste, as they are both composed chiefly
of bone.

90

ZOOLOGY

The teeth are numerous, and situated in all parts of the
front of the jaws, mouth, tongue, and branchiae. They vary
much in form ; in general, they are used more as a means of
entangling their food, than for masticating it, a few orders
only having round grinders. The teeth are simply attached to
the palate, or external surface of the bones of the jaw, not
indented into sockets, as in the other vertebrata.

The stomach of fishes is simple, as well as the intestinal
canal, and their digestion rapid. In a great proportion
of fishes, there is immediately below, and in the hollow
of the spine, an air bag, which communicates either with the
gullet, or the branchia?, or with both. Attached to this, are
certain muscles, which, by acting on this bag. compress or
permit it to expand at the will of the animal ; by this means,
the air is so modified, as to render the body lighter or heavier,
so as to permit of the animal’s easy ascent or descent in the
water. To fishes that live in deep seas, where their range
may be a mile or two of perpendicular depth, this contrivance
is indispensable. Flat fishes that inhabit shallowwater, as the
ray or flounder, have no such air bag.

As the progressive motions of fishes are all caused by hori¬
zontal movements of the body, the muscular fibres range in
a direction from the head to the tail, and have thus a greater
uniformity of action than in terrestrial animals. In some, the
colour of the muscles is reddish, in the greater proportion
white. The greatest muscular power resides in the parts con¬
nected with the tail.

166. Fishes propagate by spawn. The roe, or egg bag, is
contained in the female, the milt in the male. The spawn is
deposited in the sand of shallow seas and rivers, and the
development of the young is left to the heat of the sun and
air. Fishes are amazingly prolific. The spawn of the carp
contains two hundred thousand ; that of the herring, thirty
thousand ; the flounder, upwards of a million ; the cod, three
millions. Many fishes are migratory, and their movements
are from deep seas to shallow, and from the arctic regions to the
more temperate latitudes. They thus migrate, to procure
particular kinds of food, and to deposit their spawn. The
generality of fishes, however, like terrestrial animals, are more
fixed to certain localities, than might at first be supposed from
the fluctuating nature of the element in which they live. It is
believed that salmon continue to frequent the same rivers
during spawning time for successive generations.

FISHES.

91

Fishes are supposed to be long lived ; and instances are
recorded of pike having existed for two hundred and sixty
years.

They are not devoid of instincts, although their habits are
not easily ascertained. They may be tamed, so as to feed
from the hand. And they will come to be fed at stated
periods, thus indicating the power of memory.

Fish form a light and nutritious food, and are of great im¬
portance in an economical and commercial view.

Isinglass is the glutinous matter of the skin and bone of the
sturgeon and other fishes.

167- There are two great divisions of fishes, — those with a
bony skeleton, and the chondropterygii, or cartilaginous.

ORDER I. ACANTHOPTERYGII, Spi.xj Fins.

168. With spines supporting the whole, or the first rays of
the dorsal fin, or where the fin is wanting a few free spines.
Spines also supporting the first rays of the anal, and one to the
ventral fins. This order comprehends numerous families of
the ordinary fishes, among which are, —

Percoides — perches.

Buccce Loricatce — mailed cheeks,
gurnards.

Squamipennes—chsetodon.
Scomberaidcs — mackarel, sword-fish.

Thcutycs — sturgeon.
Mugcloidcs — mullet.

Gobioidcs — blenny.
Laberoides — laberes.

ORDER II. MALACOPTERYGII ABDOMEN AXIS, Sovt Fbouto.

169. Distinguished by the position of the ventral fins, which
are suspended to the under part of the belly behind the
pectorals, without attachment to the bones of the shoulder.
The genera is numerous, and comprehends most of the fresh
water fishes.

Scdmonidcs — salmon, trout. Caprinitke — carp, cohitis, anableps,

Clupece, herring.

Esoixs — pike, flying-fish. Srfurida’ — electric eel.

ORDER III. MALACOPTERYGII SUBRACHIATA.

170. Ventral fins inserted under the pectorals, the pelvis
directly suspended to the bones of the shoulder.

Gadus — cod, haddock, whiting.

Discoboli — lump-sucker, remora.

piani — (plcuronectes , side swimmers) plaice, flounder, sole.

02

ZOOLOGY.

ORDER IV. MALACOPTERYGII APODES.

171. Elongated slender body ; no ventral fins; thick skin;
small opercula opening by a hole or tube.

ArtguiUiformcs — eel, conger, gymnotus, ophidia.

ORDER V. LOPHOBRANCHII, Tutted Gills.

172. Gills divided into small tufts, arranged in pairs, and
covered by a large operculum, with a single orifice ; body
covered with shield-like plates. Species generally small, with
thin muscles.

Smgnathus — hippocampus, pegasus, solenostomus.

ORDER VI. PLECTOGN ATHI.

173. With imperfect bony skeleton ; and, as the name im¬
plies, cheeks united by a suture. Opercula concealed under
a thick skin ; no ventral fins. Some of the genera, as the
cephalus, seem as if the body were cut off by the shoulders.

Diodon — porcupine fish. Csphalus — sun fish.

Tetraodon. Triodon.

Ostracion — file fish.

The porcupine fish have large air bags ; and when fully
inflated, their bodies are rendered so buoyant as to float on the
surface of the water. Their thick covering of sharp spines
guarding them against the attacks of enemies.

dlOYDROPTERYGII, Cabtihqlvocs Fishes.

174. The fishes of this division have a cartilaginous skeleton,
the calcareous matter being deposited in small grains. Cranium
formed of a single piece, without sutures or joinings. In
some the branchiae are free ; in others fixed, and communicate
externally by holes.

The order with free branchiae comprehends, —

Accipenser — sturgeon. Spatularia — paddle fish.

Chinurra — arctic chimera.

PACK YDER MATA.

93

The second order with fixed branchiae includes, —

Sdachii — shark.
Zygcena.

Prestis — saw fish.
Myxine.

Raid — ray, skate, torpedo.
Squatina — angel fish.
Pctromyzon — lamprey.

175. M. Agassiz has classified fishes according to the form
of the scales, and thus divides them into four orders.

1. Placoidiak.
Broad, plated.

2. Ga NOT DEAN.
Shining scales.

3. Ctenoidean.
Comb shaped.

4. Cycloidean.
Circular.

No. 29.

Skin irregularly covered with ena¬
melled plates, often of large size.
Sometimes small points like shagreen.

i This order comprehends all the car¬
tilaginous fishes of Cuvier, except
the sturgeon.

Enamelled scales, with brilliant
surface, angular, rhomboidal ; formed

- of horny or bony plates. Of the
sixty genera of this order, fifty are

^fossil and extinct.

Scales pectinated on their posterior
margin like the teeth of a comb,
laminae of horn or bone, but no
enamel, as the perch. This order

- comprehends the acanthoptyregii of
Cuvier, with the exception of the
smooth-scaled families, and with the
addition of the pleuronectes, or flat

^flsb.

' Scales smooth, with a simple mar¬
gin, and frequently ornamented or
indented with various figures or pat-

- terns on the upper surface. Lamin*
of horn or bone, without enamel.
Embracing chiefly the malacop.tyregii

^ of Cuvier.

9 i

ZOOLOGY.

SECTION XVI.

DIVISION II. — MOLLUSC A, Soft Awimals.

176. In this division of animals there is no skeleton nor
vertebrated canal. The body is composed of soft parts, in
some unprotected except by skin, in others covered with a
shell.

The nervous system consists of certain ganglionic knots
dispersed in different points, the chief of which, corresponding
to the brain, is around the oesophagus. These ganglions form
a circle with more or less complete connection.

The respiratory organs are diversified ; some breathing air
with organs resembling lungs, others being furnished with
bran chi®, and inhaling fresh or salt water.

They have a heart, and double circulation, with white or
bluish coloured blood, thinner and containing less fibrine than
that of the vertebrata. Their stomachs are various, either
simple or compound, and they have the liver generally largely
developed.

Their muscles are attached to their 6kin or to the shelly
coverings in which they reside, and admit of contractions and
relaxations, by which various degrees of locomotion are pro¬
duced, but they have no limbs for extension or sudden
movements.

They have great irritability, which remains after the body-
lias been divided into pieces. The skin is naked and secretes
a mucilage from its pores.

Almost all these animals have a prolongation of the skin,
wlijch covers part or the whole of the body, called a mantle.

The naked mollusca are those in which the mantle is small
and narrowed into a simple disk, or pipe, or sac, or divided in
the form of fins.

Those which have the mantle more largely developed are
covered by it and are called testaceous or shell mollusks.

Shells are of various forms and colours according to the
families to which they belong. They are composed of carbo¬
nate of lime, or of albuminous or horny matter, and are formed
by an exudation from the skin of the animal, either in parallel
and successive laminae or in crowded vertical filaments.
These shells are generally unconnected with the animal, and

MOLLUSCA.

95

yet they are increased in growth, and repaired, when damaged,
by a secretion similar to that of the nails, claws, or hair of
other animals. Shells are either univalve or of one piece,
simple or whorled ; bivalve, divided into two halves and
hinged at the umbo; or multivalved, having more than two
parts, and connected by membranes. The mouths of many of
the whorled shells, as the snail, are covered by an operculum
formed either of homey or calcareous matter.

177. The number of the senses possessed by the various
orders of the mollusca is very irregular ; a few only have eyes,
still fewer have the sense of hearing. The organ of smell is
not present in any of the class, yet it has been supposed they
have the perception of odours through their porous skin.
Touch and taste are the senses possessed by the whole in
common. Their instincts are extremely limited, and their
developments are for the most part confined to the mere
organic functions necessary for existence.

Their fecundity is great. Some are viviparous, producing
their young with the shell already developed ; others are ovi¬
parous. In some the two sexes are contained in the same
animal.

CLASS I — CEPHALOPODA, Legs on the Head.

178. The mantle unites to form a muscular sac containing
the viscera. The head is surrounded by arms or tentacula, pro¬
vided with suckers. A heart, with two ventricles ; respire by
branchiae ; mouth with horny jaws ; two eve9 ; ear ; swim
with the head backwards, and move in all directions with the

No. 30.

a tbe tentacula surrounding the head ;
b the stomach and intestinal canal ;

the dotted body, the liver ;
c the anus ;

d the heart and branchiae.

The genera are : —

head undermost.

Sepia, cuttle fish.

Nautilus.

Argonauta.

Bdlemnites.

Ammonites.

Nummulites.

9G

ZOOLOGY.

The cuttle fish is remarkable for its ink-bag containing a
carbonaceous fluid, which it emits when pursued in order to
darken the water and aid its escape. The argonauta inhabits
a light shell, and erects two membranes for sails. The nauti¬
lus has a hollow multilocular, or many-chambered shell, and a
sipbuncle penetrating these cells, by which it modifies the
pressure on the contained air, and renders its shell lighter or
heavier than water, by which means it sinks to the bottom or
floats on the surface of the ocean. The bellemnites and am¬
monites are extinct families.

CLASS II. — PTEUOPODA, Fis Legs.

179. Bodies formed like a sack, but without tentacula.
Two fins placed on each side of the mouth, by which they
swim. Branchiae, a vascular net-work in the fins ; indistinct

y

eyes. The clio, cymbulia pneumodermon, are the few species
known.

CLASS III. — GASTEROPODA, Bhlly Walkers.

180. A fleshy disk under the abdomen by which they crawl ;
mantle on the back, covered, in most genera, by a shell. Head
with from two to six tentacula ; eyes on the head, or at the
points of the tentacula, or awanting. A single heart ; some
respire air, others have aquatic branchiae.

Organs of digestion various. A numerous class, divided into
orders according to the position and form of the branchiae ;
including, —

Pulmonea — snails.

A’ ud ibra nch iata — doris, triton, thetis.

Pertenff/ranchiata — trochus, buccina, murex, &c.

Scutibranchiata — halyotis.

Cj/clobranchiata — patella chiton.

CLASS IV. — ACEPHALA, Headless.

181. Without heads; a mouth concealed in the folds of the
mantle ; the mouth doubled like the leaves of a book, with the
body between ; the branchiae fringed ; the heart simple ; the
ovaries beside the fringe of the branchiae ; covered with a
bivalve or multivalve shell, furnished with a strong muscle to
shut the shell ; some with a foot for locomotion.

MOLLUSCA.

97

No. 31.

h the heart ; m the mouth ; i tlie
intestine passing through the blood¬
vessel ; the white sack in the centre
is the stomach surrounded by the
liver ; b the fringed branchiae ; below
is the ovary ; /the foot ; g g power¬
ful muscles which open and shut the
two valves of the shell.

This is a numerous class, among which will be found the
following genera : —

Oslracea — oyster, pecten, pinna, avicola.

Mytilacea — muscle, crassatella.

Chamacea — chama, tridacna.

Cardiacea — cockle, donax, cyclas, venus.

Inclusa — solen, pholas, teredo.

Acephala nuda — aseidi, pyrosoma.

Many animals of this class are prized as food. In the oyster
and muscle pearls are found. The byssus, or silken threads of
the muscle, are filaments by which the animal anchors itself to
stones. The pholades have the power of boring conical holes
in shale and hard rocks. They are furnished with a fleshy
proboscis, and it is a matter of doubt whether these perforations
are made with this instrument, aided, as in some species, by
an acid secretion, or whether they are produced by the serrated
surface of the shell.

CLASS V. — BRACHIOPODA, Armed Legs.

182. Body with a double mantle ; furnished with two fleshy
arms, with numerous filaments ; the mouth, between the base
of the arms, covered with bivalve shells, fixed to one spot.
Only three genera, — Lingula , terebratulu, orbicula. Numerous
species of the terebratula are now extinct.

CLASS VI. — CIRRHOPODA, Drush-Legged.

182. Body enveloped by a mantle, and covered with testa¬
ceous pieces ; mouths with lateral jaws, and abdomen furnished
with numerous pairs of cirri ; heart situated at the back, and
branchiae on each side ; approaching, in structure, some of the
Crustacea of next division. There are two genera, — anatifu,
barnacles, and balanus.

G

98

ZOOLOGY.

SECTION XVII.

DIVISION III. — ARTICDLATA, Jointed Animals.

184. The animals of this division have an external covering,
which may be called their skeleton, and their bodies and limbs
are divided into joints or articulations. Like the vertebrata,
their power of locomotion is great, and they can leap, run, and
fly ; a few families only, with soft bodies, being restricted to
crawling on the ground. The nervous system is confined to a
chain of ganglionic knots, a rudimentary brain being found
around the oesophagus. The circulation is in some carried on
bv a simple heart, and the respiration by branchiae ; in others
a dorsal vessel contains the blood, which is aerated by means
of air tubes, with holes or stigmata, opening on the external
surface ; a few have red, the others white blood. The jaws
are lateral and move from without inwards. There is no
organ of smell ; but the other senses are possessed either in
whole or in part, by the different classes of the division.
There arc four classes of the articulata.

CLASS I.— ANNULATA, or Rinoed.

185. These are red blooded, and the circulation is carried
on by a heart, and bloodvessels. The branchiae extend
over the body, or they are placed towards the head. The
body is elongated, and divided into numerous lings; the first
ring containing the mouth and the organs of sense. There are
no jointed feet, but in their place setae or bristles. The body
is naked, or protected with a sheath formed of shell or extra¬
neous materials. The animals are chiefly aquatic, with the
exception of the earth-worm. There are three orders, —

Tubicula — serpula, saholla, terebella, amphitrite.

Dorsibranchia — nereis, aphrodita.

Abranchia — earth-worm, nais, leech, gordius.

The calcareous tubes of the serpula, are seen covering rocks,
stones, and the shells of other animals. The terebella burrolvs
in the sand of the sea shore, and collects around its glutinous
sheath, fragments of sand, shells, and sea weed, for its protec¬
tion. The aphrodita aculeata, is beautifully tinged with
vivid colours. The earth-worm is deprived of most of the

CitUel’ACEA.

99

senses, yet its touch is exquisite, and it has instincts which
guide it to its food, and enable it to construct a nest of small
pebbles, straw, and wood, at the entrance of its hole. The
leech has a series of stomachs, and although its usual food is
water, and the minute substances it contains, it also pierces
the skin with three cartilaginous teeth, and sucks the blood of
animals.

CLASS II. — CRUSTACEA, Shell-covered.

No. 32.

186. These animals have a jointed body, and jointed feet,
covered in whole or in part with a series of plates of calcareous
substance, enveloping the body and limbs, while the muscles

and soft parts are contained
wdthin. The heart b is situated
on the back, and communicates bv
vessels with the branchiae, which
are placed either below the body,
at the base of the legs, in the form
of laminae, or tufts, or on the legs
themselves, or tail, as at f The
mouth is furnished with palpi, which serve as lips ; the
stomach a is seen in the centre, surrounded by the liver, (the
dotted part,) and terminates in the intestinal tube, which
passes on to the tail. The nervous system, composed of a
chain of ganglions, is situated below the viscera, as seen at d.
The antennae e project in front, and are organs of touch, and,
perhaps, smell. The eyes are situated on a jointed moveable
pedicle. They are generally carnivorous, and live, with few
exceptions, in the water. In the crab, lobster, &c. three teeth
are found within the stomach. They change their calcareous
shells several times in course of their life, and have the singular
power of renewing lost limbs.

187. The malacostraca have a solid and entire covering of
shell with ten or fourteen feet, the two large anterior ones
furnished with opposing claws. The ova are attached to the
exterior surface of the abdomen. The crab, lobster, land crab,
&c. belong to this subdivision.

The hermit crab has the posterior part of its body uncovered,
and takes possession of any empty shell it can find, as a pro¬
tection, and which it occupies as a house.

The annual migration of the land crab, from the mountains to
the sea shore, in order to deposit its spawn, is a curious mani¬
festation of the instincts of animals.

ZOOLOGY.

100

188. The entomostraca, or insects with shells, are so minute,
as to be almost invisible to the naked eye. They are covered
with a thin shell, of one or two pieces ; have numerous feet
fitted for swimming, and their integuments partake of the
horny composition of insects. They have two, or more fre¬
quently one, eye. They are aquatic, and generally fresh water
animals. Among the genera are, — Monoculus, nicothoe, limulus ,
and the fossil trilobites.

CLASS III.— ARACHNIDES, SPIDERS.

189. The arachnides are distinguished from insects, which
in several respects they closely resemble, by their respiratory
organs. These are situated under the abdomen, and consist, in
one class, of a heart and sacs corresponding to lungs communi¬
cating with the air by stigmata ; and in the other, of tracheae or
tubes opening by two stigmata near the anus, and without a
heart.

The animals of this class have no wings, but generally eight
legs, terminated by hooks. They are oviparous, but undergo
no change of form like insects, merely casting their skin.
The head can scarcely be distinguished from the thorax.
They have two organs in front, corresponding to imperfect
antenna?, which they use as mandibles to seize and break down
their food. Their eyes ( osceUi ) are of simple structure, and
vary from eight or more, to four or two. Sometimes they
are so extremely imperfect, as almost to disappear. The
spiders feed on insects, or larger animals ; other species are
parasitical, living on the bodies of larger animals, and some,
as mites, live on cheese, some on vegetable matter.

No. 33. 190. The Pulmonaria respire by lungs ;

> the stigmata, from two to eight, opening in the

v \r ") / > posterior and lower part of the abdomen. They
have eight legs, ar>d from six to eight eyes,
v The mouth is armed with two palpi like claws.

There are two families.

Pedipalpi — tarantula, scorpion.

Ar (intides — spiders

The spiders are a numerous and curious family. They have
two little bags in the hind part of the abdomen, which secretes
« Haiti from which their webs are spun, and which is of the
iwune nature as silk. The openings of these bags are pierced

SPIDERS.

101

by several minute orifices, and the slender threads ioin into
one immediately after exposure to the air. With these cords
they construct a circular web, divided into numerous meshes,
by which they entangle flies, on which they prey. The female
also envelops her eggs in a bag of this silk.

The gossamer threads seen so plentifully glittering in an
autumn sun, are supposed the first spinnings of the young
lycosa, a family of spiders, of which the tarantula, or poisonous
spider of Italy, is a member.

All the spiders secrete a poisonous fluid, which, by their
bite, they instil into their victims when these are found too
large or powerful for their slender toils. The mygale family
are the largest, some of them covering a circular space of
from six to seven inches in diameter. Some of these are a
match for humming-birds and small pigeons. They live in
silk-lined cases, and holes under stones, and in the bark and
leaves of trees. Scorpions have an elongated jointed body
and legs, with claws not unlike the Crustacea. The tail is
six-jointed, long and slender, and at the tip is a sting through
which issues a poisonous fluid, capable of producing alarming
and serious effects on the human body.

191. The Trachearia^ are distinguished by their respira¬
tory organs, being composed of branching tubes, which convey
the air to their blood, and are destitute of true circulating
organs. They consist of

Galeodes — pseudo scorpion Phalangium

Pycnogonum Acarus — mito

The acari are a numerous family, many of which are micro¬
scopic. They are found under stones, in wood, dried meat,
cheese, and in the skin and flesh of living animals. The
pustule of the itch is caused by a minute animal of this kind.
Cheese mites are oviparous, and excessively prolific. Their
young are produced with six legs, other two growing out
afterwards. The ixodes, or ticks, fasten their hooked mouth
and necks into the skin of dogs, foxes, and cattle, and increase
so as often to destroy the animals.

CLASS IV. — INSECTA, Insects.

192. Insects are so called from their bodies being divided
into several distinct parts or segments. They form the most
numerous class of animals, the amount of species already

ZOOLOGY.

102

known exceeding one hundred thousand. From the peculiari-
ties of their structure, the successive changes or metamorphoses
which they undergo, the singular instincts which they exhibit,
and the brilliancy and beauty of colour which many possess,
they have always claimed the particular attention of the natu¬
ralist.

No. 34.

a the head ;
b prothorax ;
c mesothorax ;
d metathorax ;

e dorsal vessel extending along
the abdomen ;

i i stigmata, with vessels leading
to the trache® ;
f f antennse ;
g mandibles or jaws ;
h palpi or lips.

With the exception of one family, myriapoda , the body of
insects is divided into three parts ; the head, a, on which are
the antennae, eyes, mouth, and palpi ; the thorax, or corslet,
composed of three parts, b, c, d , to which are attached the
legs and wings ; and the abdomen, e, i, i, in which are con¬
tained the viscera and respiratory apparatus. Insects have no
heart ; but in place of it a dorsal vessel, e, running along the
back, which contains the white blood of their bodies. The
air is admitted to this fluid by stigmata or holes on each side
of the abdomen, i, i, from which ramify minute vessels, joining
two larger branchiae, which traverse the whole length of the
body. The stomach varies much in the different families, as
well as the intestinal canal. Connected with the digestive
apparatus are hepatic vessels and salivary glands.

The mouth is furnished with mandibles, g, or jaws, and
jointed filaments called palpi, h ; two jointed antennae or
feelers, f f of various forms in the various families, also pro¬
ject from the head. Many insects are furnished with a proboscis
or trunk.

The nervous system of most insects consists of a small
rudimentary brain, and a double ganglionic chain, extending
along the inferior part of the body. From this chain forty-five
pairs of nerves are sent off to all parts of the system. It is

INSECTS.

103

probable that many insects possess equivalents for all the
senses, although distinct organs of smell or hearing are not
visible. Besides being very delicate organs of touch, the
antennae are supposed by some to communicate the impression
of odours. The eyes are numerous in insects, and of various
forms; some being extremely simple, others compound. In
many the cornea is divided into numerous facets, each of which
is supposed to admit of distinct vision.

The wings of insects are formed of two layers of extremely
thin, dry, and elastic membrane : these are supported by
branched nervures, which intersect them in all dirctions, and
often form beautiful net-work. These veins or nervures are
hollow tubes, and serve to convey air to the juices of the ani¬
mal in the same way as the tracheae of the abdomen. The
wings of the butterfly family are studded with extremely
minute scales of all varieties of colour ; they are attached to
the membrane of the wing by a pedicle, and are ranged like
tiles on a house. Insects have either four or two wings.

The feet are jointed, and consist of a thigh-bone, tibia, or
leg, and tarsus, or toes : these latter are either hooked, or
contain hollow suckers. The generality of insects have six
feet ; the tnyriapoda, which have a great number, forming an
exception.

193. Insects are sometimes viviparous, but in general the
young are hatched from ova. These young, when first pro¬
duced, are of a different form altogether from the parent ; and it
is only after undergoing successive changes, that they acquire
their full development. This is called their metamorphosis ;
a process which the greater number of insects pass through,
and which is more or less complete in the different species.

The egg being deposited by the parent in
a suitable situation, produces a worm without
wings, which is called the larva or grub, a :
the animal has a head and mouth, and the
rudiments of palpi, but no antennae : the
body is divided into numerous joints, either
with or without feet. The stigmata or air¬
holes are situated on each side of these divi¬
sions. After feeding for a certain period,
and increasing in size, the larva now changes to the chrysalis,
pupa, or nymph, b, where it is enclosed in a hard sheath,
sometimes covered with mucous incrustations, or a silky

No. 35.

a b

ZOOLOGY.

cocoon. In this condition it remains with¬
out food for several weeks or months, pos¬
sessing the form of the perfect insect, but
with all its parts folded up ; till at last,
bursting its sheath, it comes forth a winged
animal, called imayo , c.

After pairing with its mate, and enjoying existence in this
new state for a limited period, it deposits eggs for future larvae,
and then dies. Nothing can be more singular than the metamor¬
phoses which many insects thus pass through. Some aquatic
larva, as the gnat and ephemera, live for a year or two in
water, and then changing their form, mount into the air a?
winged insects : others, as the oestrus or gad-fly, are hatched
in the intestines of the horse or cow, and then become winged
hornets ; while the cynips of the oak lives in a vegetable ball,
known as the nut-gall, previous to its passing into the form of
a fly.

The changes of other insects are less complete : some merely
cast their skins, and assume wings ; while others undergo no
change of form.

The instincts of the insect tribes are generally highly deve¬
loped. They shew great ingenuity in constructing their
houses and nests, and labour the best part of their short
existence in providing for their future young, which, however,
few of them are ever destined to behold, as their life terminates
before the slow evolution of their offspring. The joint labours
of insect communities are also of a wonderful nature ; their
wars and foragings, their attachments and dislikes, the precision
with which, in long flights, they distinguish places, and fly in
straight lines to them, the acuteness of their senses, and certain
modifications of these, apparently different from those of the
higher animals, are all matters of singular interest connected
with their history.

The metamorphosis of insects seems to be an adaptation to
suit such delicate beings for the annual changes of temperature
and the successive appearance of the plants and flowers on
which they feed. They are to some extent migratory ; yet
species are for the most part circumscribed within definite
geographical limits ; and every zone has its own peculiar insects.
In tropical regions the insect tribe are most numerous, and
have the greatest brilliancy of colours.

The sounds of insects are produced by the vibration of their

104

No. 36.

INSECTS. 10.',

wings, cr by striking t heir legs or palpi against wood or their
own horny bodies.

194. Almost every organized substance becomes the food of
insects ; some living on vegetable, others on animal matter.
There is not a plant that has not several insects which feed on
some part of it ; and no preparations of animal or vegetable
matter, in whatever condition or state of decay they may be.
are safe from the all-devouring appetites of the myriads of
winged beings, which are continually swarming in the earth
or in the air.

In this way insects are of service in ridding the earth of
matters which would be offensive and deleterious to other
beings ; while they themselves, on the other hand, afford food
to many kinds of birds, reptiles, and fishes.

The insects of direct use to man are, the honey-bee, the
silk-moth, cochineal-fly, that furnishes the scarlet dye, the
blistering-fly, and the locust, which is eaten by some nations.

195. Cuvier divides insects into twelve orders, founding his
distinctions on the presence or absence of wings, and on their
form and texture.

196. Order I. Myriapoda. Centipedes. Body
without wings, elongated, and composed of a
number of equal sized joints, with two pair of feet
proceeding from each. These feet amount to
twenty-four and upwards, and increase in number
with the age of the animal. Undergo no meta¬
morphosis. The julus, glomeris, and scolopendron.
live under stones, and in sandy places.

197- OrderII. Thysanoura. Wingless insects,
with six feet and a tail, or appendages like feet to
aid them in leaping. They undergo no metamor¬
phosis. The lepisma is found in crannies of old
wood ; the podura, a minute black insect, is fre¬
quently seen in great numbers on the surface of
stagnant waters.

198. Order III. Parasita. Without wings ;
six legs; undergo no metamorphosis; are parasites
living on the bodies of other animals. There is only
one genus, pediculus, or louse, including many
species which attach themselves to the skins of
animals, feed on the blood, and deposit their glutinous eggs on
the integuments or hair.

No. 37.

106

ZOOLOGY.

No. 41.

wings,

joining

margin,

elytra.

No. 40. 199. Order IV. Suctoria. Without

wings ; the mouth composed of three pieces,
which unite to form a hollow proboscis ; un¬
dergo a metamorphosis ; hind legs strong,
and formed for leaping. The various specks
of fleas form the sole family of this order.

200. Order V. Coleoptera. With four
the upper part hard and crustaceous,
in a straight line along the inner
formed for protection, and called
The inferior, or true wings, are
folded transversely. In some species these
are wanting, but the elytra are always pre¬
sent. The antennae of various folrns, and for the most part
composed of eleven joints ; two mandibles, with one or two
palpi in each ; two or more compound eyes. The coleoptera
undergo a metamorphosis. The larva is a worm with a scaly
head ; the pupa is inactive, and requires no food ; their habita¬
tions, and mode of production, varies with the different species.
Some are aquatic, some carnivorous, and others live on vege¬
tables.

This order is by far the most numerous of the insect tribe ;
and the variety of forms, lustre, and beauty of the different
families, render it one of the most interesting. There are
four divisions marked out by the number of joints in the tarsi,
and the form of the antennae.

The various kinds of beetles, the dytisci, or water beetles,
the blistering fly, the lady-bird, the glow-worm, fire-fly, and
numerous others, belong to this order.

No. 42. 201. Order VI. Orthoptera.

With soft, semi-membranous elytra,
and straight wings, folded longitu-
nally, with longitudinal nervures.
Undergo a semi-metamorphosis. All
the genera are terrestrial, some are carnivorous, the greater
number feed on vegetables.

There are two families. The cursoria, with legs formed
for running, as the cockroaches, mantis, ear-wigs. The
saltatoria , with large hind legs and thighs adapted for leaping,
as the grasshoppers, locust, mole cricket.

1 NSEC 'i to.

107

No. 43. 202. Order VII. Hemiptera. Having

elytra half membranous. The mouth destitute of
mandibles or palpi, but furnished with a sucking
apparatus, composed of four pieces. They
undergo no metamorphosis. The cimex, or
bug, the cicada?, the aphis, and the cochineal
insect, belong to this order. The numerous
family of aphides, or plant lice, are gregarious, and are found
in great numbers on plants, the succulent juice of which forms
their food. Some of these have wings, and others are wing¬
less. During the first part of the season, all the young pro¬
duced are females, and males only make their appearance
towards the end of summer.

No. 44. 203. Order VIII. Neuroptera.

The body elongated, with soft integu-
ments ; four wings, traversed by a net-
* work of nervures, with extended man¬
dibles and straight palpi ; the joints of
the tarsi generally entire : the antennae
setaceous. Divided into three families,
many of which are carnivorous ; some undergoing complete,
and others imperfect metamorphosis. The libellula, or dragon
fly, the ephemera, or day fly, the ant lion, the termes, or white
ant, and phryganea, or caddis flies, belong to this order. The
libellula, or dragon fly, may be styled the lion of insects. It
hovers in the air, with its large glittering wings, and darts
upon smaller flies with great velocity. The larva of the
ephemera is an aquatic animal ; the imago rises from the water
in the evening, and only exists in this last state for a few hours.
The caddis worms are also aquatic, and construct houses for
their tender bodies of straws, wood, and empty shells. The
ant lion forms a pit to entrap its prey. The white ants con¬
struct large and curious nests, and are voracious and destruc¬
tive animals.

204. Order IX. Hymenoptf.ua. Furnished
with four membranous wings, but less reticu¬
lated than the neuroptera. The female fur¬
nished with a sting, or an ovipositor. They
undergo a complete metamorphosis. The
larva of some are carnivorous, others live on
vegetables, and the perfect insects on the
saccharine matter in the nectaries of flowers. The ichneu-

No. 45.

ZOOLOGY.

108

mon, cynips, &c. furnished with an ovipositor, by which they
pierce wood, and other bodies, to deposit their eggs, form
one division ; the ants and bees constitute another, and are
remarkable for their habits, for their varieties of sex, and their
living in communities.

205. Order X. Lepidoptera. With four broad wings,
covered on both sides with minute scales, often of brilliant
colours. Mouth furnished with a proboscis, which rolls up
circularly ; palpi very small ; antennae of various forms, and
jointed. They pass through a complete
metamorphosis. The larvae are known as
caterpillars. These larvae live on leaves,
wood, ■woollen stuff, fur, leather ; they
change their skins four times before passing
into the chrysalis form. Many spin a cocoon
to enclose themselves, formed of silk or mucilage, mixed with
raspings of wood, leaves of trees, or earthy matter. Some
remain in this condition only a few days, two generations being
produced in a season. Others lie in the pupa state during the
winter, and part of the spring, and come forth exactly at the
period when the particular plants on which they feed, and
deposit their eggs, are in perfection. In this order there are
three divisions, — the diurna, including the butterflies, which
fly about, and feed during the day ; the sphinxes, which
generally appear in the morning or evening ; and the nocturna,
or moths, which only make their appearance in the evening,
and during the night. The beauty and variety of these insects,
and the perfect manner in which they may be preserved, cause
them to be highly prized by collectors.

206. Order XI. Rhipiptera. With fan¬
like wings, and the rudiments of elytra on
the anterior extremity of the thorax ; man¬
dibles lancet-shaped ; two large eyes, and
filiform antennae. The larvae live on the
bodies of wasps. There are only two known
genera, — sti/Iops and xenos.

207. Order XII. Diptera. Insects with
two membranous wings, and two moveable
bodies above these, called halteres. A pro¬
boscis, or sucker, composed of from two to six
pieces. Tips of the legs furnished with two
hooks, and frequently with concave suckers.

No. 47.

No. 46.

RADIATA.

100

Undergo metamorphoses. The larvae are without feet. The
gnats, mosquitoes, tipula hornets, gad flies, house fly, ail
belong to this order. They feed on fluids, the juices of animal
bodies, putrid flesh, and many pierce the skin, and suck the
blood of living animals. The flesh fly is very prolific, and the
larvae come to maturity in a few days ; they are voracious
feeders, too, and thus whole carcasses are consumed by them
in so short a space of time, that Linnaeus has remarked, that
a few of them will consume a dead horse as quickly as would
a lion.

The larvae of the gnat are aquatic animals, and may be seen
in summer floating in myriads, in lakes and rivers, the body
being covered with numerous setaceous filaments, which are
the branchiae.

SECT. XVIII.

DIVISION IV _ RADI ATA.

208. This last division of animals embraces several classes
which cannot well be brought under one definition, except in
thus far, that they partake of the simplest structure of the
descending scale of animated existence.

The term radiated is intended to express a form of the
nervous system, in the greater number, in which the nervous
filaments radiate from one or more centres, while Zoophytes
expresses the plant-like form of the other classes, in which,
for the most part, a distinct nervous system is not perceptible.

With the exception of a few of the echinodermata, no traces
of a circulating vascular system, or of respiratory organs, are
perceptible. In the greater proportion there is a mouth with
a stomach, or series of stomachs, an intestinal tube, and an
ovary for the production of ova. In some the body is simply
a sac or stomach, with or without an orifice, corresponding to
a mouth ; while, in the polypes, the stomach forms a hollow-
in the gelatinous mass of the body.

The senses are confined to those of touch and taste, and in
the very lowest tribes, little more than the irritability of vege¬
tables is manifest.

CLASS I.— ECHINODERMATA, Spine-Skinned.

209. These animals are covered with a skin, and frequently
supported by a sort of crustaceous skeleton, furnished with

ZOOLOGY.

] 10

moveable spines, which act as arms or suckers. There is a
mouth in the centre leading to a series of stomachs, and an
intestinal tube ; a vascular system communicating with an
intestine, and respiratory organ ; and nervous filaments tra¬
versing the body.

The asterias, or star-fish, is an animal
illustrative of this class, with a radiated
body, and mouth in the centre. The
number of the rays vary in the different
species. In these rays are contained the
viscera. The whole surface of the skin is
porous, and the under side, where is situated
the mouth, is studded with moveable suckers, or tentacula, by
which the animal seizes its prey and moves from place to place.
These animals have such powers of reproducing lost parts, that
whole rays, when torn off, are speedily renewed ; and even a
single remaining ray will reproduce all the others.

The echinus, or sea-urchin, is another well known animal of
this class. It is protected by a globular shell with spines ; the
mouth is in the centre, and is furnished with five teeth inserted
into a five-sided frame of calcareous matter. The intestine is
voluminous and attached spirally to a membrane lining the
shell. The ovaries are also very large, and form the eatable
part of the animal.

The spatanyus has an irregular heart-shaped shell, covered
with very small spines, divided interiorly into four or five
unequal compartments.

The encrinife has a jointed stem, which is fixed to a rock,
with numerous smaller jointed tentacula at the top surrounding
the mouth, in the centre. Many extinct species of these are
found in a fossil state.

Another order of this class, the apoda, are without spines,
their bodies having a coriaceous covering. The siphunculus
has an elongated cylindrical form, and burrows in the sand of
the sea-shore.

CLASS II. — ENTOZOA, Intestinal Worms.

210. This class of animals, of which there are about a
thousand species, live within the bodies of other animals, and
are found in the brain, liver, intestines, and even the heart and
blood-vessels. In these localities they live and propagate, and
cannot exist in any other situation. Many animals have pecu-

No. 49.

ANIMALCULES.

Ill

liar species of these worms which are found in no others.
How the ova are transmitted from one individual to another
has been a circumstance so difficult to explain that some
theorists have resorted to the idea of equivocal generation,
contending that these animals have sprung from the living fibre
of the cavities in which they reside. All the analogies of
nature, however, and the fact that these entozoa, even of the
simplest structure, have ovaries, and produce abundance of
ova, entitle us to suppose that they, in common with all other
organized beings, spring from a parent of the same species.

Of these animals there are two divisions : —

Nematoidea, with an intestinal canal, mouth, anus, and
generative organs, as the fxlaria , or guinea- worm, the uscuris,
or round-worm, oxyuris , strongylus.

Parenchemata, body of cellular sub¬
stance, with ramified canals, and covered
with a skin with a mouth or sucker, or a
stomach with or without a mouth, us the
Ucnia, or tape-worm, fasciola. Hytudid, a,
Cysticercus, b.

CLASS III. — INFUSORIA, Infusory Animai.cui.es.

211. The animals of this class, although so minute as to be
invisible to the naked eye, yet have been ascertained to possess
an organization more complicated than some of those we have
just enumerated. They are called infusory, because it is
chiefly in infusions of vegetable matter that they are discovered.
If a few stalks of hay, or the leaves or stems of plants, be put
into a little water, and allowed to remain for a week or two,
a drop of the fluid, especially from that portion where a thin
pellicle has been formed on the top, when viewed under
a good microscope, will exhibit a little world of active,
busy beings, in the full tide of enjoyment. The smallest and

simplest forms are the monads, a , three
millions of whom can find room in the
circumference of a single drop of water.
The volvox ylobator b is a s' apeless
gelatinous mass, which appears frequently
to change its form, c represents the
manner in which some animalcules mul¬
tiply, by dividing their bodies into two
halves, d are three of the Leucophrys

No. 51.

a

4

No. 50.

a b

ZOOLOGY.

\ 12

patuia, a very common and active animalcule, with cirri around
the head, and the appearance of an internal stomach, branching
into numerous sacs, e the vibrio aceti, or paste and vinegar
eels, f the rotatoria, or wheel animalcule, so called from
several circular cirri around its head, which keep continually
revolving.

CLASS IV.— ACALEPHA.

No. 52. 212. These animals have a round gelatinous

body, with few indications of an internal orga¬
nization. They float in the sea by alternate
contractions and dilatations of their pulpy sub¬
stance. The medusa, of which there are several species,
varying from twelve inches in diameter, to the minutest point,
belong to this class. They are familiar, as jelly-like masses,
frequently cast ashore on our beaches. The smaller species
are abundant in the arctic seas, and form the principal food of
the whale.

The physalia , or Portuguese man-of-war, rendered buoyant
from its bladder shape, floats along the surface of the sea,
forming its crest into a sail.

CLASS V.— POLYPI.

213. A singular and numerous class of animals, having a
cylindrical or conical body, with tentacula surrounding the
mouth. The stomach is a hollow in their gelatinous body,
and the mouth generally serves as an anus. They multiply
by sending off shoots or buds from all parts of the body
except the tentacula. There is a simple ovary also which
produces ova at certain periods.

The actinia, or sea anemony, is fixed to rocks by its fleshy
body. It is often brilliantly coloured, and the expansion or
retractation of its numerous tentacula alters its shape and
appearance. When fully expanded, it resembles a flower —
hence its name. There are of these numerous species.

No. 53. The hydra, or fresh water polype,

is found attached to leaves and reeds
in slow running streams. It moves
4,® about by bending its body, or using

its tentacula, which are capable of
elongation to the extent of several inches. With these

POLYPI,

1)3

it seizes on worms, on which it feeds. Their bodies, when
cut into pieces, soon assume as many new forms. They can
also be turned outside in, without suffering any inconvenience.
After swallowing their food, and extracting its nourishment,
they void the indigestible parts by the mouth. They are
stimulated and attracted by light, and are active and voracious

The coralifcri include the sertularia ,
a, tubularia cellularia , corallina, b,
flustra.

These polypes inhabit cells formed of
carbonate of lime. They are grega-
reous ; the young forming their cells
above the parents, and thus, in the
course of years, a branched plant-like
substance is produced, well known as
coral.

In tropical seas, these coral zoophytes form reefs of thousands
of miles in extent.

Our ancient limestone beds appear to have been produced in
the same manner, for fossil corallines are found in abundancy
in such beds.

little animals.

No. 54.

a

TABLE OF CLASSIFICATION

DIVISION I. — VERTEBRATA.

Bimana — man.

Quadrumana — monkeys.

/ Cheiroptera — bats.

) Insectivora — mole, hedgehog.
Carnana < Carnivora_ dog, li0n, bear.

m a MM ATT A J v Amphibia seal.

i Marsupialia — opossum , kanguroo.
Rodentia — squirrel, mouse, hare.

Edentata — sloth, ant-eater.
Pachydcrmata— elephant, horse.
Ruminanlia — camel, deer, sheep.

Cetacea — whale.

AVES.

TEBIMrNCK.

Rapaces— eagle, hawk, owl.
Omni cores — crow, magpie.
Insect i cores — thrush , wren.
Granivores — lark, bunting.
Zygodactyli — cuckoo, parrot.
Anisodactyli — nuthatch.
Alcyones — king-fisher.

" Chclidones— swallow.
Columbce — pigeon.

Gallhne — cock.

A lector ides — t rumpeter.
Cursores — ostrich, emu.
Grallatores — plovers.

Pin tiati pedes — coot
Palm i pedes — ducks.

^ Inertes — dodo.

Rl'.l’TlLl A.

/ Chelonia — tortoise.

) Sauria — crocodile, chameleon,
j Ophidia — serpents.

\ Bat rack ia — frog, syren.

CUVIER.

r Accipteres.
Passerines.
Conirostres.
Scansoriee.
Gallinaccie.
Grallatorice.
Palmii>edes.

1‘ISC’ES.

AGASSIZ.

f A can thopterygu — perch, mackerel. / Placoides

| Malacopterygii— salmon, herring. j Ganioules.

Lophobranch i i — pipe tisli, pegasus. , j Ctenoides.

[ Plectoemathi — sun tisli, diodon. \Cycloide t.

{ Chonnroptcryyii — shark, sturgeon.

OF THE ANIMAL KINGDOM,

II. DIVISION— MOLLUSCA.

CEPIIALOPODA — cuttle, nautilus.
PTEROPODA— clio hyalea.
GASTEROPODA — snail, limpet.
ACEPHALA — oyster, muscle.
BRACHIOPODA — ligula terebratula.
CIRRHOPO DA— barnacle.

III. DIVISION— ARTICULATA.

ANNULATA.

CRUSTACEA.

ARACIINIDES.

INSECT A.

{Tubicula — scrpula terrebella.
Dorsibranchia — nereis, aphrodita.
Abranchia — earth worm, leech.

( Malacostraca — crab, lobster.

( Entomostraca — monoculus.

( Pulmonaria — mygale, spider.

\ Tracliearia — tarantula, scorpion, mite.
' Myriapodes — julus, centipede.
Thysanoura — lcpisma.

Parasita — louse.

Suctoria — flea.

Coleoptcra — beetles.

Orthoptera — grasshopper.

"i Hemiptcra — aphis, bug.

Neuroptera — dragon fly, ephemera.
Hymcnoptera — ant, bee.

Lepidoptera — butterfly, moth.
Ilhipiptera — stylops.

„ Diptera — house fly, gnat.

IV. DIVISION— RADIATA.

ECHINODERMATA.
ENTOZOA.
INFUSORIA.
ACALEPII A.

POLYPI.

{

Pedicellata — star fish, sea urchin.
Apoda — sipunculus, lithodermis.
Nematoidea — guinea worm, ascaris.
Parcnchymata — hydatid, fluke.
Rotifer a — wheel animal, hydatina.
Polygastrica — monad, volvox.
Simplicia — medusa.

Hydrostatica — physalia.

Carnosi — actinia.

Gelatinosi — hydra
Coralliferi — tubipore , serf ularia.

LIST OF WORKS ON ZOOLOGY.

Cuvier’s Rkgne Animal, 4 vols. Ovo.

_____ _ Translated by M'Murtrie, 8vo. cuts.

_ _ _ Enlarged by Griffiths, 8 vols. plates.

Elements de Zoologie, rar H. Milne Edwards, 3 vols. 8vo.
Linnaeus’ System of Nature, by Turton, 4 vols. 8vo.

Buffon’s Natural History, General and Particular, 8 vols.

Shaw’s Zoology, 14 vols. plates.

Blummenbach’s Manual of Natural History, by Gore, 1 vol. 8vo.

_ Comparative Anatomy, 1 vol. 8vo.

Grant’s Comparative Anatomy, 1 vol. 8vo.

Pritchard’s Natural History of Man.

Pennant’s British Zoology, 4 vols. 8vo.

- Arctic Zoology.

- Indian Zoology.

Richardson’s Northern Zoology.

Fleming’s Philosophy of Zoology, 2 vols. 8vo.

- British Zoology, 1 vol. 8vo.

Roget’s Animal Physiology, Bridgewater Treatise, 2 vols. 8vo.
Tiediman’s Comparative Physiology.

Mayo’s Human Physiology.

Bostock’s Physiology.

Fletcher’s Rudiments of Physiology.

Temminck Manuel d’ Ornithologie, 2 vols. 8vo.

Lamarck Anim. Sans Vertebres, 7 vols. 8vo.

Bewick’s British Birds, 2 vols. 8vo. woodcuts.

Selby’s British Birds, 2 vols. plates.

Wilson’s American Ornithology, 3 vols. 4to.

Audubon’s American Ornithology.

Artedi Ichthyology, 1 vol. 8vo.

De Lacdpede Hist. Nat. de Poissons, 5 vols. 4to.

Yarrel’s British Fishes, cuts.

Latreille 'J

Reaumur > French works on Insects.

De Geer j

Kirby and Spense, Entomology, 3 vols. 8vo.

Donovan’s Natural History of British Insects, 18 vols. royal 8vo.
M'Lcay’s norm Entomologicae.

Brown’s Conchology of Great Britain and Ireland, I vol. 4to. plat
Ellis’s Natural History of Corallines, 1 vol. 4to.

Johnston’s British Zoophytes, 2 vols. plates.

G L O S S A 11 Y.

Abdomen, The belly
Absorb, Absorption. The minute
mouths of the vessels of the skin
and other parts of the body have
the power of taking up or absorbing
fluids, air, &c.

Albumen, Animal jelly, as the white
of egg

Alimentary, Serving as food, belong¬
ing to food

Amphibious, Animals which live both
in the water and on land
Annulated, Ringed
Annular, Consisting of rings
Antenna ;, Two slender bodies placed
on the heads of insects and other
animals

Articulata, Those animals having a
jointed structure, but no proper
bones

Articulations, Junctures or joinings
Aurelia, A pupa, the second state of
an insect

Bicuspid, Having tw*o points
Bifurcated, Divided into two branches
Bimana, Two-handed
Branchiae. Gills of fishes and reptiles
Byssus, A beard, common in muscles,
pinnae, &c.

Calcareous, Composed of lime or
chalk

Caudal, Relating to the tail
Canine teeth. The sharp pointed teeth
on each side of the four cutting cen¬
tral teeth of animals
Carinated, Keeled
Carnivora, Flesh-devouring animals
Carnivorous, Flesh-eating, that of
which flesh is the proper food
Carpus, Bones of the hand
Cartilage, Gristle

Cere, A skin which covers the base of
the bills of some birds
Chyme, The pulpy fluid when first
digested

Chyle, The digested fluid, after an ad¬
mixture of bile

Ciliated, Edged with parallel hairs,
bristles, or appendages, like the
eyelids

Cirri, Tendrils
Cirrous, Like a tendril
Class, A term designating one of the
principal divisions of the animal
kingdom, including orders, genera,
and species.

Clavicle, The collar bone
Cocoon, The nest which caterpillars
spin for themselves before their
transformation into the pupa state
Coriaceous, Like leather
Crustaceous, Consisting of a crust
composed of carbonate, and phos¬
phate of lime, and animal matter
Cutis, The under skin
Digestion, The process by which food
is converted into nourishment for
the body

Dorsal, Relating to the back
Echinated, Bristled like a hog, set
with spines

Elongated, Lengthened, drawn out
Elytra, Hard membranous substances
covering the wings of various in¬
sects, such as beetles, Ac.

Enamel, The hard outer covering of
the teeth

Epidermis, The outer or scarf skin
Exude, To issue out
Farina, A tine mealy or scaly sub¬
stance covering the wings of insects
Filament, A small thread
Fluvialile, Of, or belonging to, fresh
water

Foliated, Leaved
Fourchette, A fork, hence
Furcated, Branched
Ganglion, A knotted nervous cord
Gelatin, Viscous, stiff, cohesive mat¬
ter, a jelly extracted from animal
substances by solution in water, but
not in alcohol

Gcmmiparous, Animals that produce
young by luls or slips from the
body

Genus, Plural genera; a family, or
kind of animals having a general
resemblance to each other, but con¬
taining different species
Gills, A series of flaps or thin folds on

GLOSSARY.

118

each side of the head of fishes, and
some other animals, through which
water constantly passes ; the air
which it contains being absorbed or
taken into their blood
Gizzard, The strong muscular sto¬
mach of birds

Gland, A knot of vessels like an acorn
secreting organs

Granivorous, Grain feeding animals
Heart, A strong, hollow, muscular
substance, which circulates the
btood through the blood-vessels of
the body

Herbivora, Those animals which feed
on grasses and herbs
Imago, An insect when it has become
a winged fly

Jncisory teeth, The front cutting teeth
in the upper and under jaws of
quadrupeds

Infusoria, Animals found in infusions
of vegetables and other liquids
Instinct, The power which guides
animals in their various operations
Intercostal, Placed between the ribs
Intestinal, Belonging to the bowels
Intestinal worms, Animals living in
the intestines of other larger beings
Iridescent, Shining, with changeable
colours

Irritability, A contracting of orga¬
nized fibres, on the application of
any stimulus

Lachrymal, Of, or belonging to tears
Lacteals, Vessels in the intestines that
convey the chyle

Lamellar, Consisting of films or plates
Laminae, Thin plates, laid one coat
above another

Larva, Grub, or worm, the first stage
of an insect before it becomes a fly
Ligament, A solid body, softer than a
cartillage, but harder than a mem¬
brane, which fastens the bones and
articulates them together for mo¬
tion ; in bivalve shells, the substance
which connects the valves
Linear, Composed of lines
Littoral, Of, or belonging to the shore
Lungs, Substances consisting of num¬
berless cells, through which the air
is breathed that contributes to the
life of the body

Mammae , The breasts or paps of ani¬
mals

Mammalia, Those animals which
have teats, and which suckle their
young with milk

Mandibles, The upper and under
chaps of a bird’s bill, or jaws of an
insect

Masticate, To chew the food
Maxillae, Or jaws

Migration, The flight of birds from
one country to another at certain
regular periods of the year
Mollusca, Those animals having a
fleshy body and no bones

Mucus, A slimy secretion
MultHocidar, Many- chambered, con¬
sisting of several divisions
Muscles, The fleshy substance on the
bones of animals, by which they
move their limbs and bodies
Nerves, Small white cords proceeding
from the brain, and going to every
part of the body, by which sensation
is communicated.

Nocturnal, Js’iglit-feeding animals
Nympha, Pupa, or chrysalis, the
second stage of insect life
(Esophagus, The tube leading from
the mouth to the stomach
Opercidum, The gill-cover of fishes;
a lid, by which some of the univalve
and multivalve shells are closed
Order, A term in Zoology, which
includes genera and species
Organism, Animal structure
Organized, Bodies having vessels and
parts necessary for life
Osseous, Of a bony substance
Ovary, The organ which contains the
germs or eggs

Oviparous, Animals that bring forth
their young from eggs
Ovipositor, An instrument by which
insects deposit their eggs
Ovoviviparous, Animals which pro¬
duce eggs containing living young
Paehydermata, Animalshaving thick
skins

Palpi, Projections from the lower
jaws of insects

Palmated, Webbed, as in the feet of
some water birds
Papillae, Small dots or pimples
Parasitical, Living on some other
body

Pectinated, Resembling the teeth of a
comb

Pectoral, Relating to the breast
Phosphorescent, Emitting light in the
dark

Prehensile, Hanging
Proboscis, A moveable tube attached
to the head of several animals, par¬
ticularly insects

Progression, The act of walking or
moving

Pupa, Or nympha, the second stage
of insect life

Quadrumana, Having four hands
Quadruped, Having four feet
Radiated, Rayed, furnished with
rays

Reptile, A name applied to the class
of serpents, frogs, tortoises, &c.
Rete mucosum. The mucous network
between the outer and inner skin,
which is black in the negro
Retractile, Capable of being drawn
back

Rodentia, Animals that gnaw with
the fore teeth

Ruminantia, Animals which chew
the cud.

GLOSSARY.

119

Sac, A small bag or pouch
Secretion, The production of animal
matters by vessels and glands
Sensation, The power of feeling,
seeing, hearing, &c.

Serrated, Like the teeth of a saw
Setaceous, Bristly, covered with bristles
Siphunculus, A cylindrical canal, per¬
forating the partition in many -cham¬
bered shells

Skeleton, A frame of bones
Sped s, Belonging to the same genus
or family, but having distinct
characters

Spiracles, Air-tubes, leading to the
branchiae of insects
Spine, The back bone
Spinous, Having spines like a hedge¬
hog

Stellated, Starred, consisting of star-
like figures

Stimulus, Any thing that excites or
acts on the animal frame
Striated, Scored, or covered with fine
thread-like lines
Tarsus, The foot bones
Teals, The nipples of animals which
suckle their young
Tentacula, Feelers or horns
Testaceous, Consisting of carbonate of
lime and animal matter, as in the
shells of molluscous animals
Tissue, A thin membrane or web

Thorax, The chest or upper part of
the body

Torpidity, A state of sleep that
animals fall into during winter, in
which they neither eat, nor move,
nor have the usual warmth of body
Trachea, The wind-pipe leading to
the lungs

Turbinated. Shaped like a top or pear
Umbo, In bivalve shells, the round
part which turns the hinge
Unorganized, Matter without any
structure necessary for carrying on
life

'Variety, Is when one species differs
in some little degree from that of
another

Vascular, Consisting of vessels
Ventral, Belonging to the belly
Vertebra, The bones which compose
the spine or back-bone
Vertebrata, Those animals having a
spine, or series of small bones eom-
isising the back

Vcrtebrated, l’rovided with vertebras

Villose,

Villous

^ Downy

V i seer a , The contents of the internal
cavities as the lungs, intestines, &c.
Viviparous, Animals which bring
forth their young alive
Zoology, ('(acr, and }.oyo;,) a discourse
on animals

TDK END.

EDINBURGH :

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