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The embryo which has begun its development in the act of germination.

In embryonic development, a vesicle filled with fluid, formed from the morula by the divergence of its cells in such a manner as to give rise to a central space, around which the cells arrange themselves as an envelope; an embryonic form intermediate between the morula and gastrula. Sometimes used as synonymous with ga…

An Irish or Welsh melody for the harp, sometimes of a mournful character.

A small plane or surface, usually capable of adjustment but not of manipulation, for preserving lateral balance in an aëroplane or flying machine.

A flying machine, or a small plane for experiments on flying, which floats in the air only when propelled through it.

One who flies in an aëroplane.

A plant deriving its sustenance from the air alone; an aërophyte.

In hotels, aplan upon which guests pay for both room and board by the day, week, or other convenient period; -- contrasted with European plan.

different curvatures, so combined as to remove spherical aberration; -- said of a lens. Aplanatic focus of a lens (Opt.), the point or focus from which rays diverging pass the lens without spherical aberration. In certain forms of lenses there are two such foci; and it is by taking advantage of this fact that the best…

Freedom from spherical aberration.

A nonmotile gamete, found in certain lower algæ.

A plane used for cutting out grooves and inlaying strings and bands in straight and circular work.

An aëroplane with two main supporting surfaces one above the other.

A plane used for working the upper surface of staircase rails.

See Coplanar.

Flattened to a level surface. [R.]

Contemplation. [Obs.] Chaucer.

Given to contemplation; meditative. [R.] Coleridge.

A plan of distributing surplus by giving to each policy the excess of premiums and interest earned thereon over the expenses of management, cost of insurance, and the policy value at the date of computation. This excess is called the contribution of the policy.

Convex on one side, and flat on the other; plano-convex.