|Page 120||Contents - 'The Origin of Species' by Charles Darwin||prev page next page|
ANIMALCULE.--A minute animal: generally applied to those visible only by the microscope.
ANNELIDS.--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 earth-worms, and the leeches.
ANTENNAE.--Jointed organs appended to the head in Insects, Crustacea and Centipedes, and not belonging to the mouth.
ANTHERS.--The summits of the stamens of flowers, in which the pollen or fertilising dust is produced.
APLACENTALIA, APLACENTATA or APLACENTAL MAMMALS.--See MAMMALIA.
ARCHETYPAL.--Of or belonging to the Archetype, or ideal primitive form upon which all the beings of a group seem to be organised.
ARTICULATA.--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).
ASYMMETRICAL.--Having the two sides unlike.
ATROPHIED.--Arrested in development at a very early stage.
BALANUS.--The genus including the common Acorn-shells which live in abundance on the rocks of the sea-coast.
BATRACHIANS.--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.)
BOULDERS.--Large transported blocks of stone generally embedded in clays or gravels.
BRACHIOPODA.--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.
BRANCHIAE.--Gills or organs for respiration in water.
BRANCHIAL.--Pertaining to gills or branchiae.
CAMBRIAN SYSTEM.--A series of very ancient Palaeozoic rocks, between the Laurentian and the Silurian. Until recently these were regarded as the oldest fossiliferous rocks.
CANIDAE.--The Dog-family, including the Dog, Wolf, Fox, Jackal, etc.
CARAPACE.--The shell enveloping the anterior part of the body in Crustaceans generally; applied also to the hard shelly pieces of the Cirripedes.
CARBONIFEROUS.--This term is applied to the great formation which includes, among other rocks, the coal-measures. It belongs to the oldest, or Palaeozoic, system of formations.
CAUDAL.--Of or belonging to the tail.
CEPHALOPODS.--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, Cuttle-fish, Nautilus.)
CETACEA.--An order of Mammalia, including the Whales, Dolphins, etc., having the form of the body fish-like, the skin naked, and only the fore limbs developed.
CHELONIA.--An order of Reptiles including the Turtles, Tortoises, etc.
CIRRIPEDES.--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.
COCCUS.--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.
COCOON.--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."
COELOSPERMOUS.--A term applied to those fruits of the Umbelliferae which have the seed hollowed on the inner face.
COLEOPTERA.--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.
COLUMN.--A peculiar organ in the flowers of Orchids, in which the stamens, style and stigma (or the reproductive parts) are united.
COMPOSITAE 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, Dandelion, etc.)
CONFERVAE.--The filamentous weeds of fresh water.