[ noun ] a mass of undifferentiated cells from which an organ or body part develops <noun.body>
Blastema \Blas*te"ma\, n.; pl. {Blastemata}. [Gr. bla`sthma bud, sprout.] (Biol.) The structureless, protoplasmic tissue of the embryo; the primitive basis of an organ yet unformed, from which it grows.