. "the outermost membranous sac enclosing the embryo in higher vertebrates (reptiles, birds and mammals)"@en-us . "0"^^ . . . "01472939-n"^^ . . . "the outermost membranous sac enclosing the embryo in higher vertebrates (reptiles, birds and mammals)"@en-us . . . . "0"^^ . "chorion"@en-us . . . . "101472939"^^ . "chorion"^^ . . . . . . . . . "101395849"@en-us . . . .