It must contain within itself a nucleus of truth.
--I. Taylor.
2. (Astron.) The body or the head of a comet.
3. (Bot.)
(a) An incipient ovule of soft cellular tissue.
(b) A whole seed, as contained within the seed coats.
4. (Biol.) A body, usually spheroidal, in a cell or a
protozoan, distinguished from the surrounding protoplasm
by a difference in refrangibility and in behavior towards
chemical reagents. It is more or less protoplasmic, and
consists of a clear fluid (achromatin) through which
extends a network of fibers (chromatin) in which may be
suspended a second rounded body, the nucleolus (see
{Nucleoplasm}). See {Cell division}, under {Division}.