noun. The outer layer of a blastula that gives rise to the ectoderm after gastrulation.

noun. In botany, a name applied by Richard to a second small cotyledon which is found in wheat and some other grasses.

noun. In embryology, the outer or external blastodermic membrane or layer of cells, forming the ectoderm or epiderm: distinguished at first from hypoblast, then from both hypoblast and mesoblast. See cut under blastocæle.

noun. The outer layer of the blastoderm; the ectoderm. See blastoderm, delamination.

noun. the outer layer of a blastula that, after gastrulation, becomes the ectoderm

"It has long been known that certain cells of an early mammalian embryo—known as epiblast cells—can naturally become primordial germ cells, which, in turn, give rise to sperm or eggs."

blastoderm  delamination