I am indebted to the kindness of Mr. W. S. Dallas for this
Glossary, which has been given because several readers have complained
to me that some of the terms used were unintelligible to them. Mr.
Dallas has endeavoured to give the explanations of the terms in as
popular a form as possible.
EDITOR'S NOTE: This
glossary did not appear in the first edition and has been reproduced
here directly from the sixth edition
- Forms or groups of animals or plants which
deviate in important characters from their nearest allies, so as not
to be easily included in the same group with them, are said to be
ABERRATION (in Optics)
- In the refraction of light by
a convex lens the rays passing through different parts of the lens are
brought to a focus at slightly different distances, this
is called spherical aberration; at the same
time the coloured rays are separated by the prismatic action of the
lens and likewise brought to a focus at different
distances, this is chromatic
- Contrary to the general rule.
- An organ is said to be aborted, when its
development has been arrested at a very early stage.
- Albinos are animals in which the usual
colouring matters characteristic of the species have not been produced
in the skin and its appendages. Albinism is the state of being an
- A class of plants including the ordinary
sea-weeds and the filamentous fresh-water weeds.
ALTERNATION OF GENERATIONS
- This term is applied to a
peculiar mode of reproduction which prevails among many of the lower
animals, in which the egg produces a living form quite different from
its parent, but from which the parent-form is reproduced by a process
of budding, or by the division of the substance of the first product
of the egg.
- A group of fossil, spiral, chambered
shells, allied to the existing pearly Nautilus, but having the
partitions between the chambers waved in complicated patterns at their
junction with the outer wall of the shell.
- That resemblance of structures which depends
upon similarity of function, as in the wings of insects and birds.
Such structures are said to be analogous,
and to be analogues of each other.
- A minute animal: generally applied to
those visible only by the microscope.
- A class of worms in which the surface of the
body exhibits a more or less distinct division into rings or segments,
generally provided with appendages for locomotion and with gills. It
includes the ordinary marine worms, the earthworms, and the leeches.
- Jointed organs appended to the head in
Insects, Crustacea and Centipedes, and not belonging to the mouth.
- The summits of the stamens of flowers, in
which the pollen or fertilising dust is produced.
APLACENTALIA, APLACENTATA or Aplacental Mammals
- See Mammalia.
- Of or belonging to the Archetype, or ideal
primitive form upon which all the beings of a group seem to be
- A great division of the Animal Kingdom
characterised generally by having the surface of the body divided into
rings called segments, a greater or less number of which are furnished
with jointed legs (such as Insects, Crustaceans and Centipedes).
- Having the two sides unlike.
- Arrested in development at a very early stage.
- The genus including the common Acorn-shells
which live in abundance on the rocks of the sea-coast.
- A class of animals allied to the Reptiles,
but undergoing a peculiar metamorphosis, in which the young animal is
generally aquatic and breathes by gills.
(Examples, Frogs, Toads, and Newts.)
- Large transported blocks of stone generally
imbedded in clays or gravels.
- A class of marine Mollusca, or
soft-bodied animals, furnished with a bivalve shell, attached to
submarine objects by a stalk which passes through an aperture in one
of the valves, and furnished with fringed arms, by the action of which
food is carried to the mouth.
- Gills or organs for respiration in
- Pertaining to gills or branchiæ.
- A Series of very ancient
Palæozoic rocks, between the Laurentian and the Silurian. Until
recently these were regarded as the oldest fossiliferous rocks.
- The Dog-family, including the Dog, Wolf,
Fox, Jackal, &c.
- The shell enveloping the anterior part of
the body in Crustaceans generally; applied also to the hard shelly
pieces of the Cirripedes.
- This term is applied to the great
formation which includes, among other rocks, the coal-measures. It
belongs to the oldest, or Palæozoic, system of formations.
- Of or belonging to the tail.
- The highest class of the Mollusca, or
Soft-bodied animals, characterised by having the mouth surrounded by a
greater or less number of fleshy arms or tentacles, which, in most
living species, are furnished with sucking-cups. (Examples,
- An order of Mammalia, including the Whales,
Dolphins, &c., having the form of the body fish-like, the skin
naked, and only the fore-limbs developed.
- An order of Reptiles including the Turtles,
- An order of Crustaceans including the
Barnacles and Acorn-shells. Their young resemble those of many other
Crustaceans in form; but when mature they are always attached to other
objects, either directly or by means of a stalk, and their bodies are
enclosed by a calcareous shell composed of several pieces, two of
which can open to give issue to a bunch of curled, jointed tentacles,
which represent the limbs.
- The genus of Insects including the Cochineal.
In these the male is a minute, winged fly, and the female generally a
motionless, berry-like mass.
- A case usually of
silky material, in which insects are frequently enveloped during the
second or resting-stage (pupa) of their existence. The term
`cocoon-stage' is here used as equivalent to `pupa-stage.'
- A term applied to those fruits of
the Umbelliferæ which have the seed hollowed on the inner face.
- Beetles, an order of Insects, having a
biting mouth and the first pair of wings more or less horny, forming
sheaths for the second pair, and usually meeting in a straight line
down the middle of the back.
- A peculiar organ in the flowers of Orchids, in
which the stamens, style and stigma (or the reproductive parts) are
COMPOSITÆ or COMPOSITOUS PLANTS
- Plants in
which the inflorescence consists of numerous small flowers (florets)
brought together into a dense head, the base of which is enclosed by a
common envelope. (Examples, the Daisy,
- The filamentous weeds of fresh water.
- A rock made up of fragments of rock or
pebbles, cemented together by some other material.
- The second envelope of a flower usually
composed of coloured, leaf-like organs (petals), which may be united
by their edges either in the basal part or throughout.
- The normal coincidence of one phenomenon,
character, &c., with another.
- A bunch of flowers in which those springing
from the lower part of the flower stalk are supported on long stalks
so as to be nearly on a level with the upper ones.
- The first or seed-leaves of plants.
- A class of articulated animals, having
the skin of the body generally more or less hardened by the deposition
of calcareous matter, breathing by means of gills.
(Examples, Crab, Lobster, Shrimp, &c.)
- The old generic term for the Beetles known
as Weevils, characterised by their four-jointed feet, and by the head
being produced into a sort of beak, upon the sides of which the
antennæ are inserted.
- Of or belonging to the skin.
- The wearing down of land by the action of
the sea or of meteoric agencies.
- The wearing away of the surface of the
land by water.
DEVONIAN SYSTEM or formation
- A series of
Palæozoic rocks, including the Old Red Sandstone.
DICOTYLEDONS or DICOTYLEDONOUS PLANTS
- A class of
plants characterised by having two seed-leaves, by the formation of
new wood between the bark and the old wood (exogenous growth) and by
the reticulation of the veins of the leaves. The parts of the flowers
are generally in multiples of five.
- The separation or discrimination of
parts or organs which in simpler forms of life are more or less
- Having two distinct
forms. Dimorphism is the condition of the appearance of
the same species under two dissimilar forms.
- Having the organs of the sexes upon
- A peculiar form of Greenstone.
- Of or belonging to the back.
- A peculiar order of Quadrupeds,
characterised by the absence of at least the middle incisor (front)
teeth in both jaws. (Examples, the Sloths
- The hardened fore-wings of Beetles, serving as
sheaths for the membranous hind-wings, which constitute the true
organs of flight.
- The young animal undergoing development within
the egg or womb.
- The study of the development of the
- Peculiar to a given locality.
- A division of the class Crustacea,
having all the segments of the body usually distinct, gills attached
to the feet or organs of the mouth, and the feet fringed with fine
hairs. They are generally of small size.
- The earliest of the three divisions of the
Tertiary epoch of geologists. Rocks of this age contain a small
proportion of shells identical with species now living.
- Insects allied to the May-fly.
- The totality of the animals naturally
inhabiting a certain country or region, or which have lived during a
given geological period.
- The Cat-family.
- Having become wild from a state of cultivation
- The totality of the plants growing naturally in
a country, or during a given geological period.
- Flowers imperfectly developed in some
respects, and collected into a dense spike or head, as in the Grasses,
the Dandelion, &c.
- Of or belonging to the foetus, or
embryo in course of development.
- A class of animals of very low
organisation, and generally of small size, having a jelly-like body,
from the Surface of which delicate filaments can be given off and
retracted for the prehension of external objects, and having a
calcareous or sandy shell, usually divided into chambers, and
perforated with small apertures.
- Containing fossils.
- Having a faculty of digging. The Fossorial
Hymenoptera are a group of Wasp-like Insects, which burrow in sandy
soil to make nests for their young.
- FRENA). A small band or fold of skin.
- FUNGUS). A class of cellular plants, of
which Mushrooms, Toadstools, and Moulds, are familiar examples.
- The forked bone formed by the union of the
collarbones in many birds, such as the common Fowl.
- An order of Birds of which the
common Fowl, Turkey, and Pheasant, are well-known examples.
- The genus of birds which includes the common
- A swelling or knot from which nerves are
given off as from a centre.
- Fishes covered with peculiar enamelled
bony scales. Most of them are extinct.
- A minute vesicle in the eggs of
animals, from which development of the embryo proceeds.
- A period of great cold and of enormous
extension of ice upon the surface of the earth. It is believed that
glacial periods have occurred repeatedly during the geological history
of the earth, but the term is generally applied to the close of the
Tertiary epoch, when nearly the whole of Europe was subjected to an
- An organ which secretes or separates some
peculiar product from the blood or sap of animals or plants.
- The opening of the windpipe into the
oesophagus or gullet.
- A rock approaching granite in composition, but
more or less laminated, and really produced by the alteration of a
sedimentary deposit after its consolidation.
- The so-called Wading-birds (Storks,
Cranes, Snipes, &c.), which are generally furnished with long
legs, bare of feathers above the heel, and have no membranes between
- A rock consisting essentially of crystal of
felspar and mica in a mass of quarts.
- The locality in which a plant or animal
- An order or sub-order of Insects,
characterised by the possession of a jointed beak or rostrum, and by
having the fore-wings horny in the basal portion and membranous at the
extremity, where they cross each other. This group includes the
various species of Bugs.
- Possessing the organs of both sexes.
- That relation between parts which results
from their development from corresponding embryonic parts, either in
different animals, as in the case of the arm of man, the foreleg of a
quadruped, and the wing of a bird; or in the same individual, as in
the case of the fore and hind legs in quadrupeds, and the segments or
rings and their appendages of which the body of a worm, a centipede,
&c., is composed. The latter is called serial
homology. The parts which stand in such a relation to each
other are said to be homologous, and one
such part or organ is called the homologue
of the other. In different plants the parts of the flower are
homologous, and in general these parts are regarded as homologous with
- An order or sub-order of Insects having
(like the Hemiptera) a jointed beak, but in which the fore-wings are
either wholly membranous or wholly leathery. The Cicadoe,
Frog-hoppers, and Aphides, are well-known examples.
- The offspring of the union of two distinct
- An order of insects possessing biting
jaws and usually four membranous wings in which there are a few veins.
Bees and Wasps are familiar examples of this group.
- Excessively developed.
- A family of Hymenopterous insects,
the members of which lay their eggs in the bodies or eggs of other
- The perfect (generally winged) reproductive
state of an insect.
- The aboriginal animal or vegetable
inhabitants of a country or region.
- The mode of arrangement of the flowers
- A class of microscopic Animalcules,
so called from their having originally been observed in infusions of
vegetable matters. They consist of a gelatinous material enclosed in
a delicate membrane, the whole or part of which is furnished with
short vibrating hairs (called cilia), by means of which the
animalcules swim through the water or convey the minute particles of
their food to the orifice of the mouth.
- Feeding on Insects.
INVERTEBRATA, or INVERTEBRATE ANIMALS
- Those animals
which do not possess a backbone or spinal column.
- Spaces left among the tissues in some of
the lower animals, and serving in place of vessels for the circulation
of the fluids of the body.
- Furnished with lamellæ or little
- LARVÆ). The first condition of an
insect at its issuing from the egg, when it is usually in the form of
a grub, caterpillar, or maggot.
- The upper part of the windpipe opening into
- A group of greatly altered and very
ancient rocks, which is greatly developed along the course of the St.
Laurence, whence the name. It is in these that the earliest known
traces of organic bodies have been found.
- An order of plants represented by
the common Peas and Beans, having an irregular flower in which one
petal stands up like a wing, and the stamens and pistil are enclosed
in a sheath formed by two other petals. The fruit is a pod (or
- A group of four-handed animals,
distinct from the Monkeys and approaching the Insectivorous Quadrupeds
in some of their characters and habits. Its members have the nostrils
curved or twisted, and a claw instead of a nail upon the first finger
of the hind hands.
- An order of Insects, characterised by the
possession of a spiral proboscis, and of four large more or less scaly
wings. It includes the well-known Butterflies and Moths.
- Inhabiting the seashore.
- A marly deposit of recent (Post-Tertiary) date,
which occupies a great part of the valley of the Rhine.
- The higher division of the Crustacea,
including the ordinary Crabs, Lobsters, Shrimps, &c., together
with the Woodlice and Sand-hoppers.
- The highest class of animals, including the
ordinary hairy quadrupeds, the Whales, and Man, and characterised by
the production of living young which are nourished after birth by milk
from the teats (Mammoe, Mammary
glands) of the mother. A striking difference in embryonic
development has led to the division of this class into two great
groups; in one of these, when the embryo has attained a certain stage,
a vascular connection, called the placenta,
is formed between the embryo and the mother; in the other this is
wanting, and the young are produced in a very incomplete state.
The former, including the greater part of the class, are called
Placental mammals; the latter, or Aplacental mammals,
include the Marsupials and Monotremes (Ornithorhynchus).
- Having mammæ; or teats (See MAMMALIA).
MANDIBLES, in Insects
- The first or uppermost pair of
jaws, which are generally solid, horny, biting organs. In Birds the
term is applied to both jaws with their horny coverings. In
Quadrupeds the mandible is properly the lower jaw.
- An order of Mammalia in which the young
are born in a very incomplete state of development, and carried by the
mother, while sucking, in a ventral pouch (marsupium), such as the
Kangaroos, Opossums, &c. (see MAMMALIA).
MAXILLÆ, in Insects
- The second or lower pair of
jaws, which are composed of several joints and furnished with peculiar
jointed appendages called palpi, or feelers.
- The opposite of albinism; an undue
development of colouring material in the skin and its appendages.
- Sedimentary rocks which have
undergone alteration, generally by the action of heat, subsequently to
their deposition and consolidation.
- One of the great divisions of the Animal
Kingdom, including those animals which have a soft body, usually
furnished with a shell, and in which the nervous ganglia, or centres,
present no definite general arrangement. They are generally known
under the denomination of `shell-fish;' the cuttle-fish, and the
common snails, whelks, oysters, mussels, and cockles, may serve as
examples of them.
MONOCOTYLEDONS, or MONOCOTYLEDONOUS PLANTS
- Plants in which
the seed sends up only a single seed-leaf (or cotyledon);
characterised by the absence of consecutive layers of wood in the stem
(endogenous growth), by the veins of the leaves being generally
straight, and by the parts of the flowers being generally in multiples
of three. (Examples, Grasses, Lilies,
Orchids, Palms, &c.)
- The accumulations of fragments of rock
brought down by glaciers.
- The law of form or structure independent
- A stage in the development of certain
Crustaceans (Prawns), in which they closely resemble the adults of a
genus (Mysis) belonging to a slightly lower
- Commencing development.
- Adapted for the purpose of swimming.
- The earliest stage in the development
of many Crustacea, especially belonging to the lower groups. In this
stage the animal has a short body, with indistinct indications of a
division into segments, and three pairs of fringed limbs. This form of
the common fresh-water Cyclops was
described as a distinct genus under the name of Nauplius.
- The arrangement of the veins or nervures in
the wings of Insects.
- Imperfectly developed females of certain
social insects (such as Ants and Bees), which perform all the labours
of the community. Hence they are also called workers.
- A semi-transparent membrane,
which can be drawn across the eye in Birds and Reptiles, either to
moderate the effects of a strong light or to sweep particles of dust,
&c., from the surface of the eye.
- The simple eyes or stemmata of Insects, usually
situated on the crown of the head between the great compound eyes.
- The gullet.
- A great series of secondary rocks, so called
from the texture of some of its members, which appear to be made up of
a mass of small egg-like calcareous bodies.
- A calcareous plate employed by many
Mollusca to close the aperture of their shell. The opercular valves of Cirripedes are those which
close the aperture of the shell.
- The bony cavity for the reception of the eye.
- An organised being, whether plant or animal.
- A term applied to those fruits of the
Umbelliferæ which have the seed straight.
- Forms or groups apparently intermediate
between and connecting other groups are said to be osculant.
OVARIUM or OVARY (in plants)
- The lower part of the
pistil or female organ of the flower, containing the ovules or
incipient seeds; by growth after the other organs of the flower have
fallen, it usually becomes converted into the fruit.
OVULES (of plants)
- The seeds in the earliest
- A group of Mammalia, so called from their
thick skins, and including the Elephant, Rhinoceros, Hippopotamus,
- The oldest system of fossiliferous
- Jointed appendages to some of the organs of the
mouth in Insects and Crustacea.
- An order of Plants (see
LEGUMINOSÆ). The flowers of these plants are called
papilionaceous, or butterfly-like, from the
fancied resemblance of the expanded superior petals to the wings of a
- An animal or plant living upon or in, and at
the expense of, another organism.
- The production of living Organisms
from unimpregnated eggs or seeds.
- Supported upon a stem or stalk. The
pedunculated oak has its acorns borne upon a footstalk.
PELORIA or PELORISM
- The appearance of regularity of
structure in the flowers of plants which normally bear irregular
- The bony arch to which the hind limbs of
Vertebrate animals are articulated.
- The leaves of the corolla, or second circle of
organs in a flower. They are usually of delicate texture and brightly
- Having flattened, leaf-like twigs or
leafstalks instead of true leaves.
- The colouring material produced generally in
the superficial parts of animals. The cells secreting it are called
- Bearing leaflets on each side of a central
- The female organs of a flower, which occupy a
position in the centre of the other floral organs. The pistil is
generally divisible into the ovary or germen, the style and the
PLACENTALIA, PLACENTATA, or Placental Mammals
- Quadrupeds which walk upon the whole
sole of the foot, like the Bears.
- Readily capable of change.
- The latest portion of the
PLUMULE (in plants)
- The minute bud between the
seed-leaves of newly-germinated plants.
- Rocks supposed to have been produced
by igneous action in the depths of the earth.
- The male element in flowering plants; usually
a fine dust produced by the anthers, which, by contact with the stigma
effects the fecundation of the seeds. This impregnation is brought
about by means of tubes (pollen-tubes)
which issue from the pollen-grains adhering to the stigma, and
penetrate through the tissues until they reach the ovary.
- Flowers having many stamens.
- Plants in which some flowers are
unisexual and others hermaphrodite. The unisexual (male and female)
flowers, may be on the same or on different plants.
- Presenting many forms.
- The common structure for
the Polyzoa, such as the well-known Sea-mats.
- Capable of grasping.
- Having a superiority of power.
- The feathers forming the tip of the wing of
a bird, and inserted upon that part which represents the hand of man.
- Projecting portions of bones, usually for
the attachment of muscles, ligaments, &c.
- A resinous material collected by the
Hive-Bees from the opening buds of various trees.
- Exceedingly variable.
- The lowest great division of the Animal
Kingdom. These animals are composed of a gelatinous material, and show
scarcely any trace of distinct organs. The Infusoria, Foraminifera,
and Sponges, with some other forms, belong to this division.
- PUPÆ). The second stage in the development of an Insect,
from which it emerges in the perfect (winged) reproductive form.
In most insects the pupal stage is passed in perfect repose.
The chrysalis is the pupal state of butterflies.
- The minute root of an embryo plant.
- One half of the lower jaw in the Mammalia. The
portion which rises to articulate with the skull is called the
- The extent of country over which a plant or
animal is naturally spread. Range in time
expresses the distribution of a species or group through the
fossiliferous beds of the earth's crust.
- The delicate inner coat of the eye, formed by
nervous filaments spreading from the optic nerve, and serving for the
perception of the impressions produced by light.
- Backward development. When an animal,
as it approaches maturity, becomes less perfectly organised than might
be expected from its early stages and known relationships, it is said
to undergo a retrograde development or
- A class of lowly organised animals
(protozoa), having a gelatinous body, the surface of which can be
protruded in the form of root-like processes or filaments, which serve
for locomotion and the prehension of food. The most important order
is that of the Foraminifera.
- The gnawing Mammalia, such as the Rats,
Rabbits, and Squirrels. They are especially characterised by the
possession of a single pair of chisel-like cutting teeth in each jaw,
between which and the grinding teeth there is a great gap.
- The Bramble Genus.
- Very imperfectly developed.
- The group of Quadrupeds which ruminate or
chew the cud, such as oxen, sheep, and deer. They have divided hoofs,
and are destitute of front teeth in the upper jaw.
- Belonging to the sacrum, or the bone composed
usually of two or more united vertebræ to which the sides of the
pelvis in Vertebrate animals are attached.
- The gelatinous material of which the bodies
of the lowest animals (Protozoa) are composed.
- The horny plates with which the feet
of birds are generally more or less covered, especially in front.
- Rocks deposited as sediments
- The transverse rings of which the body of an
articulate animal or Annelid is composed.
- The leaves or segments of the calyx, or
outermost envelope of an ordinary flower. They are usually green, but
sometimes brightly coloured.
- Teeth like those of a saw.
- Not supported on a stem or footstalk.
- A Very ancient system of
fossiliferous rocks belonging to the earlier part of the
- The setting apart of a particular
organ for the performance of a particular function.
- The central portion of the nervous
system in the Vertebrata, which descends from the brain through the
arches of the vertebræ, and gives off nearly all the nerves to
the various organs of the body.
- The male organs of flowering plants, standing
in a circle within the petals. They usually consist of a filament and
an anther, the anther being the essential part in which the pollen, or
fecundating dust, is formed.
- The breast-bone.
- The apical portion of the pistil in flowering
- Small leafy organs placed at the base of the
footstalks of the leaves in many plants.
- The middle portion of the perfect pistil, which
rises like a column from the ovary and supports the stigma at its
- Situated beneath the skin.
- Adapted for sucking.
SUTURES (in the skull)
- The lines of junction of the
bones of which the skull is composed.
- TARSI). The jointed feet of articulate
animals, such as Insects.
- Fishes of the kind familiar to us
in the present day, having the skeleton usually completely ossified
and the scales horny.
TENTACULA or TENTACLES
- Delicate fleshy organs of
prehension or touch possessed by many of the lower animals.
- The latest geological epoch, immediately
preceding the establishment of the present order of things.
- The windpipe or passage for the admission of
air to the lungs.
- Three-fingered, or composed of three
movable parts attached to a common base.
- A peculiar group of extinct Crustaceans,
somewhat resembling the Woodlice in external form, and, like some of
them, capable of rolling themselves up into a ball. Their remains are
found only in the Palæozoic rocks, and most abundantly in those
of Silurian age.
- Presenting three distinct forms.
- An order of plants in which the
flowers, which contain five stamens and a pistil with two styles, are
supported upon footstalks which spring from the top of the flower stem
and spread out like the wires of an umbrella, so as to bring all the
flowers in the same head (umbel) nearly to
the same level. (Examples, Parsley and
- Hoofed quadrupeds.
- Consisting of a single cell.
- Containing blood-vessels
- Like a worm.
VERTEBRATA: or VERTEBRATE ANIMALS
- The highest
division of the animal kingdom, so called from the presence in most
cases of a backbone composed of numerous joints or vertebroe,
which constitutes the centre of the skeleton and at the same time
supports and protects the central parts of the nervous system.
- The circles or spiral lines in which the parts
of plants are arranged upon the axis of growth.
- See neuters.
- The earliest stage in the development of
many of the higher Crustacea, so called from the name of Zoea
applied to these young animals when they were supposed to constitute
a peculiar genus.
- In many of the lower animals (such as the
Corals, Medusæ, &c.) reproduction takes place in two ways,
namely, by means of eggs and by a process of budding with or without
separation from the parent of the product of the latter, which is
often very different from that of the egg. The individuality of the
species is represented by the whole of the form produced between two
sexual reproductions; and these forms, which are apparently individual
animals, have been called zooids.