Chapter VI: Section II: Insects not undergoing Metamorphosis

10. _Thysanoura_, or spring-tail insects. These creatures are of
small size, and without wings; they are found in crevices of
woodwork, or under stones. The principal genera are Lepisma and
Podura.

11. _Parasita_, or parasitical insects, such as the louse. They are
also without wings.

12. _Myriapoda._ This order is made a separate class by many
naturalists, as the creatures contained in it are distinguished
from the true insects by the great number of their feet; by the
want of distinct divisions into thorax and abdomen; and by the
great number of segments into which the body is divided. The
principal insects in this order are included in the Linnæan genera
_Julus_ and _Scolopendra_, commonly called centipedes.

The term larva is applied to the young of all insects, included in the first nine orders, when first hatched. The different kinds have, however, other names; that is to say, the larva of a butterfly, or moth, is called a caterpillar; that of a beetle, a grub; and that of a fly, a maggot. The larva changes its skin several times, and at last goes into the pupa state, when it is called a chrysalis, an aurelia, or a nymph. Sometimes the pupa is wrapped up in a loose outer covering called a cocoon. From the pupa in time bursts forth the imago, or perfect insect. The Apterous, or wingless true insects, and the Myriapoda, which are also without wings, do not undergo any metamorphosis.

THE RADIATED ANIMALS

Are so called because their organs of locomotion, and even their internal viscera, are generally arranged in a circle round a centre, so as to give a radiated appearance to the whole body. The animals included in this class are the very lowest in the scale; they have scarcely any external senses; their movements are slow, and almost their only sign of life is a craving for food. Some of them, however, have a distinct mouth and alimentary canal, with an anal orifice; others have a bag-like stomach with a kind of mouth, through which they both take their food and reject their excrements; while others have no mouth, and appear only to absorb nourishment through pores. In the like manner, though some are oviparous, others may be propagated by division into plants. Of these Cuvier makes five classes:

I. _Echinodermata_, or sea-urchins. These animals have a leathery
or crustaceous skin or shell, commonly covered with numerous
tubercles. The mouth is generally in the centre of the animal, and
is often armed with five or more pieces of bone, which serve as
teeth; the stomach is a loose bag; the organs for respiration are
vascular; and the animals are oviparous. They are furnished with
tentacular tubes, which serve as arms or feet, and which they can
push out and draw back at pleasure; and they have yellowish or
orange-coloured blood, which appears to circulate. Cuvier divides
this class into those with feet, and those without; but Lamarck,
whose arrangement has been more generally followed, divides them
into three orders; viz.:

1. _The Fistuloides_, or _Holothurida_, which have cylindrical
bodies, leathery skins, and mouths surrounded by tentacula. These
creatures live in the sea, or in the sands on the sea-shore; the
trepang, or eatable worm of the Chinese, is one of them.

2. _The Echinides._ These are the sea-urchins, properly so called,
and the shells, when the animals are out of them, are called
sea-eggs. The Echinides live in the sea. They lay eggs, and the
roe, or imperfect eggs, occupy a large portion of the space within
the shell when the animal is still alive.

3. _The Stellerides_, or _Asterias_, are the star-fish. The mouth
in these creatures is in the middle of the lower surface, and it
has a membranous lip, capable of great dilation, but furnished with
angular projections for capturing its prey. The skin is soft, but
leathery, and it is covered on the back with spongeous tubercles,
or scales. The rays are hollow beneath, and furnished with
tentacula, by the aid of which the star-fish manages to crawl
backwards, forwards, or sideways, as the case may be, any of the
rays serving as a leader. These animals are found on the sea-shore,
forming large beds, which are washed over by the sea. _The
Crinoidea_, or stone-lilies, of which such curious fossil specimens
have been found, are nearly allied to the star-fish.

II. _The Intestina_, or _Entozoa_. The intestinal worms were
divided into two kinds by Cuvier, viz. the _Cavitaires_, including
the worms of children, and other cylindrical worms; and the
_Parenchymateux_, or flat worms; such as the fluke in sheep and the
tape-worm in human beings. The Entozoa are now universally regarded
as belonging to the Articulated or Annulose division of the animal
kingdom.

III. _Acalephæ_, or _Sea-Jellies_. These creatures are of a soft
and jelly-like substance, with a thin skin, and an unarmed mouth.
The Medusides are very numerous, and produce that beautiful
phosphorescent light noticed by voyagers in the Australian seas.
The most interesting of the Acalephes is the Portuguese man-of-war,
or Physalia.

IV. _Polyps_, or _Anthozoa_, according to Cuvier, were divided into
three orders; namely:

1. _Fleshy Polyps_ (Sea anemones);

2. _Gelatinous Polyps_ (_Hydra_); and

3. _Polyps with Polyparies_, the latter including all the various
compound zoophytes, with the Sponges. Of these the _Flustræ_, or
_Sea Mats_, and numerous allied species, have since been
recognised as belonging rather to the Mollusca, and the Sponges to
a distinct and lower group of animals than the Radiata; the
remainder have generally been divided into the following three
orders:--

1. _Helianthoida._ This order includes the actinia, or sea-anemone;
and the madrepores, sea-mushrooms, and brainstones, which live in
communities, and possess the power of secreting calcareous matters,
which they emit to form these stony substances.

2. _Asteroida._ Some of the animals belonging to this division are
called sea-pens, and others form some of the different kinds of
coral, particularly that used for necklaces, &c.

3. _Hydroida._ This order includes the fresh-water polypi, which,
it is well known, by the experiments that have been tried, may be
cut in pieces and even turned inside out without destroying life.
It must be observed that the contents of this group in Cuvier’s
system consisted of all those forms of animals which he could not,
in accordance with the knowledge possessed in his day, conveniently
place anywhere else. Within the last few years, however, great
progress has been made in the arrangement of the animals placed in
this group by Cuvier. One of the most important changes has been
the establishment of a fifth group of animals for the Infusoria and
Sponges, together with certain other creatures of very low
organisation. To these the name of PROTOZOA has been given. The
_Entozoa_ have been removed amongst the articulate animals, and
there is a growing conviction that the _Echinodermata_ will have to
be transferred to the same section. There remain, consequently, the
_Acalephæ_ and _Polyps_ of Cuvier, which form a group characterised
by their soft and generally gelatinous texture; by the existence of
peculiar cells, called thread cells, in the skin; and by their
possession of an alimentary cavity with only a single orifice. To
these the name of CŒLENTERATA has been given. They are divided
into two classes: I. The ANTHOZOA, or Polyps, including the orders
_Helianthoida_ and _Asteroida_; and II. The HYDROZOA, composed of
the Hydroid Polyps and Acalephæ, the connection between which, as
indicated in the text (p. 609), is very intimate.

V. _The Infusoria_, or _Animalcula_, are so small as to be
invisible to the naked eye, and they are all inhabitants of
liquids. Cuvier arranged them in two orders, one of which he called
_Les Rotifères_, and the other _Les Infusories homogènes_, but the
first of these divisions is now included among the Articulata. The
remainder of the Infusoria of Cuvier, with the exception of some
which are now known to be of vegetable nature, are arranged, with
the Sponges and some other animals, in a separate division, called
Protozoa, the classification of which is still in a somewhat
uncertain state. The three principal classes are those of the
_Infusoria_, the _Sponges_, and the _Rhizopoda_; but there are
other forms which will not admit of being brought under any of
these denominations. Nearly all the Protozoa are microscopic,
except when, as in the case of the Sponges, they form an
aggregation of individuals. They are very numerous, and, although
exceedingly simple in their structure, their history often
possesses much interest.

EXPLANATION

OF

TERMS USED IN NATURAL HISTORY.

_Abdomen._ The part of the body containing
the organs of digestion.
_Abdominal._ Pertaining to the abdomen.
_Amphibious._ Capable of living both on the land and in the water.
_Animalcules._ Small animals, visible only with
the assistance of the microscope.
_Annulated._ Marked with rings.
_Antennæ._ The horns or feelers of insects.
_Apex._ The top or summit of anything.
_Apical._ Situated at, or belonging to, the apex.
_Apodal._ Footless.
_Apterous._ Wingless.
_Aquatic._ Living or growing in the water.
_Bicuspid._ Having two points.
_Bifid._ Divided into two parts.
_Bifurcated._ Divided into two prongs.
_Bisulcous._ Cloven-hoofed.
_Bivalve._ With two shells.
_Branchiæ._ Gills, or organs for aquatic respiration.
_Buccal._ Pertaining to the mouth.
_Byssus._ A tuft of silky filaments produced by some Mollusca.
_Callosity._ A hard lump, an excrescence.
_Campanulate._ Bell-shaped.
_Canine._ Of the dog kind.
_Carinated._ Keeled.
_Carnivorous._ Feeding on flesh.
_Caudal._ Pertaining to the tail.
_Cere._ A skin over the base of the bill of birds._Cervical._
Belonging to the neck.
_Cetaceous._ Of the whale kind.
_Cilia._ Microscopic filaments, which,
by their constant vibration,
either cause currents in the water,
or move the animals
possessing them.
_Cinereous._ Of the colour of ashes.
_Clavate._ Clubbed.
_Cordiform._ Heart-shaped.
_Coriaceous._ Leathery.
_Corneous._ Horny.
_Crustaceous._ Covered with a shell or crust; as lobsters, crabs, &c.
_Dentate._ Toothed like a saw.
_Dorsal._ Belonging to the back.
_Elytra._ The wing-cases of insects of the beetle tribe.
_Emarginate._ Notched.
_Entomology._ A description of insects.
_Exsanguineous._ Without red blood, as worms.
_Feline._ Belonging to the cat kind.
_Ferruginous._ Of an iron or rust colour.
_Filiform._ Thread-like.
_Foliaceous._ Leaf-like.
_Frugivorous._ Feeding on fruits.
_Furcated._ Forked.
_Fusiform._ Spindle-shaped.
_Gallinaceous._ Belonging to the hen kind.
_Gelatinous._ Like jelly.
_Gemmiparous._ Capable of propagating by buds.
_Geniculate._ Bent like a knee.
_Gestation._ The time of going with young.
_Granivorous._ Feeding on grain.
_Gregarious._ Associating together.
_Hastate._ Formed like an arrow-head.
_Haustellate._ Insects with a mouth adapted for suction.
_Herbivorous._ Feeding on grass.
_Hexapod._ Having six legs.
_Hyaline._ Glassy.
_Ichthyology._ A description of fishes.
_Imbricated._ Tiled, or lying over each other.
_Incubation._ The act of hatching eggs.
_Insectivorous._ Feeding on insects.
_Intestinal._ Pertaining to the digestive organs.
_Laminated._ Covered with or divided into plates or scales.
_Larva._ The young of insects.
_Lateral._ Belonging to the side, placed sideways.
_Loricated._ Covered with hard scales or plates like
armour._Lunate._
Crescent-shaped.
_Mandibles._ Upper and lower, the two divisions of
a bird’s beak, or
the projecting jaws of an insect.
_Migratory._ Coming and going at certain seasons.
_Multivalve._ With many shells or openings.
_Nacreous._ Resembling mother-of-pearl.
_Nictitating._ Winking; applied to a membrane with which birds cover
their eyes at pleasure.
_Olfactory._ Relating to smell.
_Operculum._ A shield or cover.
_Ornithology._ A description of birds.
_Oviparous._ That lays eggs.
_Palmated._ Webbed.
_Parasitic._ Attached to and dependent on some other living body.
_Parturition._ The act of bringing forth young.
_Passerine._ Belonging to the sparrow tribe.
_Pectinate._ Resembling a comb.
_Pectoral._ Belonging to the breast.
_Pendulous._ Hanging down.
_Piscivorous._ Feeding on fishes.
_Plicate._ Folded.
_Predaceous._ Formed to pursue prey.
_Prehensile._ Capable of grasping.
_Quadrifid._ Divided into four parts.
_Quadruped._ Four-footed.
_Ramose._ Branching.
_Reptiles._ Animals of the serpent tribe, with legs.
_Rudimentary._ Small; imperfectly developed.
_Ruminating._ Chewing the cud.
_Scabrous._ Rough.
_Scapulars._ Shoulders.
_Semilunar._ In the form of a half-moon.
_Serrated._ Notched like a saw.
_Sessile._ Attached without the intervention of a stalk.
_Setaceous._ Having bristles or strong hairs.
_Spiral._ Winding like a screw.
_Squamose._ Scaly.
_Striated._ Streaked or striped.
_Subulated._ Formed like an awl.
_Sulcated._ Furrowed.
_Suture._ The line of junction of two hind parts.
_Tentacula._ The feelers of snails and other mollusca.
_Testaceous._ Covered with a shell, as oysters.
_Trifurcated._ Three-forked.
_Truncated._ Appearing as if cut off._Tubicolar._
Inhabiting a tube.
_Univalve._ With one shell or opening.
_Ventral._ Belonging to the belly.
_Vertebrated._ Having a jointed spine-bone.
_Viscera._ The organs contained in the cavities of the body.
_Viviparous._ Bringing forth the young alive.
_Webbed._ Connected by a membrane, as the toes of aquatic birds.
_Xylophagous._ Wood-eating.
_Zoologists._ Writers on animated nature.
_Zoology._ The history of animated nature.

TABLE OF CONTENTS.

BOOK I.

QUADRUPEDS, OR FOUR-FOOTED BEASTS.

POPULAR AND SCIENTIFIC NAMES OF THE ANIMALS DESCRIBED.

⁂ Where no synonyme is given, the Linnæan name is the only one in use; and when the synonymes are seldom used, they are marked thus *. When no Linnæan name is given, the animal was not described by Linnæus.