Charles Darwin: The Origin of Species by means of Natural Selection

GLOSSARY 1. GLOSSARY OF THE PRINCIPAL SCIENTIFIC TERMS USED IN THE PRESENT VOLUME. (continued)

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.