cells, mesoderm, layer, fig, endoderm, form, formation, signals, origin, section, differentiation, groove, mesenchyme, interactions, material, figure, notochord, cell, removal, outside, cap, tissues

embryonic, neural, overlying, superficial, dorsal, presumptive, oral, primitive, extraembryonic, outer, epidermal, thickened, adjacent, prospective, competent, isolated, cutaneous, ventral, lateral, ciliated, external, amniotic, apical, primary, nonneural, buccal, future, normal, amphibian, somatic, larval, foetal, aboral, placodal, thin, thick, neurogenic, anterior, invaginated, definitive, stomodeal, fetal, secondary, undifferentiated, indifferent, embryonal, cephalic, basal, facial, underlying, thinner, epithelial, transparent, bud, cranial, layered, nervous, branchial, pharyngeal, grafted, columnar, forming, transplanted, animal, trochal, intact, unmodified, trophoblastic, undetermined, induced, stomodaeal, corneal, distal, outside, posterior, delicate, specialized, chorioallantoic, otic, newt, neighboring, fused, calicoblastic, adjoining, explanted