*germinal*

a. [ See Germ. ] 1. Pertaining or belonging to a germ; as, the germinal vesicle. [ 1913 Webster ]

2. (Biol.) Of or pertaining to the germ, or germ cells, as distinguished from the somatic cells. [ Webster 1913 Suppl. ]

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. [ 1913 Webster ]