原基; 胚基; 胚莖; 芽基
Blastema \Blas*te"ma\, n.; pl. {Blastemata}. [Gr. ? bud,
sprout.] (Biol.)
The structureless, protoplasmic tissue of the embryo; the
primitive basis of an organ yet unformed, from which it
grows.
blastema
n : a mass of undifferentiated cells from which an organ or body
part develops
[also: {blastemata} (pl)]