The sphere or globular mass of cells (blastomeres), formed by the clevage of the ovum or egg in the first stages of its development; -- called also mulberry mass, segmentation sphere, and blastosphere. See Segmentation.

A pre-embryo consisting of a ball of cells

a solid mass of cells produced by successive cleavages of a fertilized ovum a few days after fertilization

endash;(L. morus = mulberry) early stage of development (12-15 cells) when conceptus is a solid ball of cells, further cell division forms the blasocyst.