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.

See Mammalia .

Of or belonging to the Archetype, or ideal primitive form upon which all the beings of a group seem to be organised.