Ger″mi‐nal (?), a. [See Germ.] Pertaining or belonging to a germ; as, the germinal vesicle.
Germinal layers(Biol.), the two layers of cells, the ectoblast and entoblast, which form respectively the outer covering and inner wall of the gastrula. A third layer of cells, the mesoblast, which is formed later and lies between these two, is sometimes included. — Germinal membrane. (Biol.) Same as Blastoderm. — Germinal spot(Biol.), the nucleolus of the ovum. — Germinal vesicle, (Biol.), the nucleus of the ovum of animals.