'Blastula' definitions:
Definition of 'blastula'
(from WordNet)
noun
Early stage of an embryo produced by cleavage of an ovum; a liquid-filled sphere whose wall is composed of a single layer of cells; during this stage (about eight days after fertilization) implantation in the wall of the uterus occurs [syn: blastula, blastosphere]
Definition of 'Blastula'
From: GCIDE
- Blastula \Blas"tu*la\, n. [NL., dim. of Gr. blasto`s a sprout.] (Biol.) That stage in the development of the ovum in which the outer cells of the morula become more defined and form the blastoderm. [1913 Webster]